diff --git a/src/modules/nostr-feed/components/SubmissionComment.vue b/src/modules/nostr-feed/components/SubmissionComment.vue
index 1dc820f..9a3ea90 100644
--- a/src/modules/nostr-feed/components/SubmissionComment.vue
+++ b/src/modules/nostr-feed/components/SubmissionComment.vue
@@ -141,16 +141,24 @@ const isOwnComment = computed(() =>
         <div class="flex items-center gap-1 mt-1 pl-5">
           <!-- Vote buttons (inline style) -->
           <button
-            class="p-1 text-muted-foreground hover:text-orange-500 transition-colors"
-            :class="{ 'text-orange-500': comment.votes.userVote === 'upvote' }"
+            :class="[
+              'p-1 transition-colors',
+              comment.votes.userVote === 'upvote'
+                ? 'text-orange-500'
+                : 'text-muted-foreground hover:text-orange-500'
+            ]"
             :disabled="!isAuthenticated"
             @click="emit('upvote', comment)"
           >
             <ChevronUp class="h-4 w-4" />
           </button>
           <button
-            class="p-1 text-muted-foreground hover:text-blue-500 transition-colors"
-            :class="{ 'text-blue-500': comment.votes.userVote === 'downvote' }"
+            :class="[
+              'p-1 transition-colors',
+              comment.votes.userVote === 'downvote'
+                ? 'text-blue-500'
+                : 'text-muted-foreground hover:text-blue-500'
+            ]"
             :disabled="!isAuthenticated"
             @click="emit('downvote', comment)"
           >
diff --git a/src/modules/nostr-feed/components/SubmissionDetail.vue b/src/modules/nostr-feed/components/SubmissionDetail.vue
index b3e97b2..0a1f0bd 100644
--- a/src/modules/nostr-feed/components/SubmissionDetail.vue
+++ b/src/modules/nostr-feed/components/SubmissionDetail.vue
@@ -143,6 +143,25 @@ async function onDownvote() {
   }
 }
 
+// Handle comment voting
+async function onCommentUpvote(comment: SubmissionCommentType) {
+  if (!isAuthenticated.value || !submissionService) return
+  try {
+    await submissionService.upvoteComment(props.submissionId, comment.id)
+  } catch (err) {
+    console.error('Failed to upvote comment:', err)
+  }
+}
+
+async function onCommentDownvote(comment: SubmissionCommentType) {
+  if (!isAuthenticated.value || !submissionService) return
+  try {
+    await submissionService.downvoteComment(props.submissionId, comment.id)
+  } catch (err) {
+    console.error('Failed to downvote comment:', err)
+  }
+}
+
 // Handle share
 function onShare() {
   const url = window.location.href
@@ -473,6 +492,8 @@ function goBack() {
             :current-user-pubkey="currentUserPubkey"
             @toggle-collapse="toggleCollapse"
             @reply="startReply"
+            @upvote="onCommentUpvote"
+            @downvote="onCommentDownvote"
           />
         </template>
       </section>
diff --git a/src/modules/nostr-feed/services/ReactionService.ts b/src/modules/nostr-feed/services/ReactionService.ts
index 09a7e2f..24adfb7 100644
--- a/src/modules/nostr-feed/services/ReactionService.ts
+++ b/src/modules/nostr-feed/services/ReactionService.ts
@@ -427,6 +427,124 @@ export class ReactionService extends BaseService {
     }
   }
 
+  /**
+   * Send a dislike reaction to an event
+   */
+  async dislikeEvent(eventId: string, eventPubkey: string, eventKind: number): Promise<void> {
+    if (!this.authService?.isAuthenticated?.value) {
+      throw new Error('Must be authenticated to react')
+    }
+
+    if (!this.relayHub?.isConnected) {
+      throw new Error('Not connected to relays')
+    }
+
+    const userPubkey = this.authService.user.value?.pubkey
+    const userPrivkey = this.authService.user.value?.prvkey
+
+    if (!userPubkey || !userPrivkey) {
+      throw new Error('User keys not available')
+    }
+
+    // Check if user already disliked this event
+    const eventReactions = this.getEventReactions(eventId)
+    if (eventReactions.userHasDisliked) {
+      throw new Error('Already disliked this event')
+    }
+
+    try {
+      this._isLoading.value = true
+
+      // Create reaction event template according to NIP-25
+      const eventTemplate: EventTemplate = {
+        kind: 7, // Reaction
+        content: '-', // Dislike reaction
+        tags: [
+          ['e', eventId, '', eventPubkey], // Event being reacted to
+          ['p', eventPubkey], // Author of the event being reacted to
+          ['k', eventKind.toString()] // Kind of the event being reacted to
+        ],
+        created_at: Math.floor(Date.now() / 1000)
+      }
+
+      // Sign the event
+      const privkeyBytes = this.hexToUint8Array(userPrivkey)
+      const signedEvent = finalizeEvent(eventTemplate, privkeyBytes)
+
+      // Publish the reaction
+      await this.relayHub.publishEvent(signedEvent)
+
+      // Optimistically update local state
+      this.handleReactionEvent(signedEvent)
+
+    } catch (error) {
+      console.error('Failed to dislike event:', error)
+      throw error
+    } finally {
+      this._isLoading.value = false
+    }
+  }
+
+  /**
+   * Remove a dislike from an event using NIP-09 deletion events
+   */
+  async undislikeEvent(eventId: string): Promise<void> {
+    if (!this.authService?.isAuthenticated?.value) {
+      throw new Error('Must be authenticated to remove reaction')
+    }
+
+    if (!this.relayHub?.isConnected) {
+      throw new Error('Not connected to relays')
+    }
+
+    const userPubkey = this.authService.user.value?.pubkey
+    const userPrivkey = this.authService.user.value?.prvkey
+
+    if (!userPubkey || !userPrivkey) {
+      throw new Error('User keys not available')
+    }
+
+    // Get the user's reaction ID to delete
+    const eventReactions = this.getEventReactions(eventId)
+
+    if (!eventReactions.userHasDisliked || !eventReactions.userReactionId) {
+      throw new Error('No dislike reaction to remove')
+    }
+
+    try {
+      this._isLoading.value = true
+
+      // Create deletion event according to NIP-09
+      const eventTemplate: EventTemplate = {
+        kind: 5, // Deletion request
+        content: '', // Empty content or reason
+        tags: [
+          ['e', eventReactions.userReactionId], // The reaction event to delete
+          ['k', '7'] // Kind of event being deleted (reaction)
+        ],
+        created_at: Math.floor(Date.now() / 1000)
+      }
+
+      // Sign the event
+      const privkeyBytes = this.hexToUint8Array(userPrivkey)
+      const signedEvent = finalizeEvent(eventTemplate, privkeyBytes)
+
+      // Publish the deletion
+      const result = await this.relayHub.publishEvent(signedEvent)
+
+      console.log(`ReactionService: Dislike deletion published to ${result.success}/${result.total} relays`)
+
+      // Optimistically update local state
+      this.handleDeletionEvent(signedEvent)
+
+    } catch (error) {
+      console.error('Failed to remove dislike:', error)
+      throw error
+    } finally {
+      this._isLoading.value = false
+    }
+  }
+
   /**
    * Helper function to convert hex string to Uint8Array
    */
diff --git a/src/modules/nostr-feed/services/SubmissionService.ts b/src/modules/nostr-feed/services/SubmissionService.ts
index b64e017..787f3e9 100644
--- a/src/modules/nostr-feed/services/SubmissionService.ts
+++ b/src/modules/nostr-feed/services/SubmissionService.ts
@@ -229,6 +229,8 @@ export class SubmissionService extends BaseService {
         onEvent: (event: NostrEvent) => this.handleEvent(event),
         onEose: () => {
           this.debug('End of stored events for submission')
+          // After loading comments, fetch their reactions
+          this.fetchCommentReactions(submissionId)
           this._isLoading.value = false
         },
         onClose: () => {
@@ -417,7 +419,7 @@ export class SubmissionService extends BaseService {
       parentId: this.getParentId(event) || rootId,
       depth: 0,
       replies: [],
-      votes: this.getDefaultVotes()
+      votes: this.getCommentVotes(event.id)
     }
 
     // Add to comments map
@@ -701,6 +703,23 @@ export class SubmissionService extends BaseService {
     }
   }
 
+  /**
+   * Get votes for a comment from reaction service
+   */
+  private getCommentVotes(commentId: string): SubmissionVotes {
+    if (this.reactionService) {
+      const reactions = this.reactionService.getEventReactions(commentId)
+      return {
+        upvotes: reactions.likes || 0,
+        downvotes: reactions.dislikes || 0,
+        score: (reactions.likes || 0) - (reactions.dislikes || 0),
+        userVote: reactions.userHasLiked ? 'upvote' : reactions.userHasDisliked ? 'downvote' : null,
+        userVoteId: reactions.userReactionId
+      }
+    }
+    return this.getDefaultVotes()
+  }
+
   /**
    * Calculate ranking scores
    */
@@ -907,6 +926,68 @@ export class SubmissionService extends BaseService {
     submission.ranking = this.calculateRanking(submission, submission.votes)
   }
 
+  /**
+   * Upvote a comment
+   */
+  async upvoteComment(submissionId: string, commentId: string): Promise<void> {
+    const comment = this.findComment(submissionId, commentId)
+    if (!comment) throw new Error('Comment not found')
+
+    if (comment.votes.userVote === 'upvote') {
+      // Remove upvote
+      await this.reactionService?.unlikeEvent(commentId)
+      comment.votes.userVote = null
+      comment.votes.upvotes = Math.max(0, comment.votes.upvotes - 1)
+    } else {
+      // Add upvote
+      await this.reactionService?.likeEvent(
+        commentId,
+        comment.pubkey,
+        SUBMISSION_KINDS.SUBMISSION
+      )
+      // If was downvoted, remove downvote
+      if (comment.votes.userVote === 'downvote') {
+        comment.votes.downvotes = Math.max(0, comment.votes.downvotes - 1)
+      }
+      comment.votes.userVote = 'upvote'
+      comment.votes.upvotes += 1
+    }
+
+    // Update score
+    comment.votes.score = comment.votes.upvotes - comment.votes.downvotes
+  }
+
+  /**
+   * Downvote a comment
+   */
+  async downvoteComment(submissionId: string, commentId: string): Promise<void> {
+    const comment = this.findComment(submissionId, commentId)
+    if (!comment) throw new Error('Comment not found')
+
+    if (comment.votes.userVote === 'downvote') {
+      // Remove downvote
+      await this.reactionService?.undislikeEvent(commentId)
+      comment.votes.userVote = null
+      comment.votes.downvotes = Math.max(0, comment.votes.downvotes - 1)
+    } else {
+      // Add downvote (ReactionService keeps only latest reaction per user)
+      await this.reactionService?.dislikeEvent(
+        commentId,
+        comment.pubkey,
+        SUBMISSION_KINDS.SUBMISSION
+      )
+      // If was upvoted, update local count
+      if (comment.votes.userVote === 'upvote') {
+        comment.votes.upvotes = Math.max(0, comment.votes.upvotes - 1)
+      }
+      comment.votes.userVote = 'downvote'
+      comment.votes.downvotes += 1
+    }
+
+    // Update score
+    comment.votes.score = comment.votes.upvotes - comment.votes.downvotes
+  }
+
   // ============================================================================
   // Sorting
   // ============================================================================
@@ -1163,6 +1244,67 @@ export class SubmissionService extends BaseService {
     return comments.find(c => c.id === commentId)
   }
 
+  /**
+   * Fetch reactions for all comments of a submission
+   */
+  private async fetchCommentReactions(submissionId: string): Promise<void> {
+    const comments = this._comments.get(submissionId)
+    if (!comments || comments.length === 0) return
+
+    const commentIds = comments.map(c => c.id)
+
+    this.debug('Fetching reactions for comments:', commentIds.length)
+
+    // Subscribe to reactions for all comment IDs
+    const filters: Filter[] = [
+      {
+        kinds: [SUBMISSION_KINDS.REACTION],
+        '#e': commentIds
+      }
+    ]
+
+    return new Promise<void>((resolve) => {
+      const subscriptionId = `comment-reactions-${submissionId}-${Date.now()}`
+
+      const unsubscribe = this.relayHub.subscribe({
+        id: subscriptionId,
+        filters,
+        onEvent: (event: NostrEvent) => {
+          // Route to reaction service
+          this.reactionService?.handleReactionEvent(event)
+        },
+        onEose: () => {
+          this.debug('End of comment reactions')
+          // Update all comment votes after reactions are loaded
+          this.updateCommentVotes(submissionId)
+          unsubscribe()
+          resolve()
+        },
+        onClose: () => {
+          resolve()
+        }
+      })
+
+      // Timeout fallback
+      setTimeout(() => {
+        unsubscribe()
+        resolve()
+      }, 5000)
+    })
+  }
+
+  /**
+   * Update votes for all comments from reaction service
+   */
+  private updateCommentVotes(submissionId: string): void {
+    const comments = this._comments.get(submissionId)
+    if (!comments) return
+
+    for (const comment of comments) {
+      comment.votes = this.getCommentVotes(comment.id)
+    }
+  }
+
   // ============================================================================
   // Utilities
   // ============================================================================