diff --git a/routers/web/repo/pull.go b/routers/web/repo/pull.go
index 74028c316..7cedeec10 100644
--- a/routers/web/repo/pull.go
+++ b/routers/web/repo/pull.go
@@ -752,11 +752,27 @@ func ViewPullFiles(ctx *context.Context) {
 	if ctx.Written() {
 		return
 	}
-	ctx.Data["CurrentReview"], err = models.GetCurrentReview(ctx.Doer, issue)
+
+	currentReview, err := models.GetCurrentReview(ctx.Doer, issue)
 	if err != nil && !models.IsErrReviewNotExist(err) {
 		ctx.ServerError("GetCurrentReview", err)
 		return
 	}
+	numPendingCodeComments := int64(0)
+	if currentReview != nil {
+		numPendingCodeComments, err = models.CountComments(&models.FindCommentsOptions{
+			Type:     models.CommentTypeCode,
+			ReviewID: currentReview.ID,
+			IssueID:  issue.ID,
+		})
+		if err != nil {
+			ctx.ServerError("CountComments", err)
+			return
+		}
+	}
+	ctx.Data["CurrentReview"] = currentReview
+	ctx.Data["PendingCodeCommentNumber"] = numPendingCodeComments
+
 	getBranchData(ctx, issue)
 	ctx.Data["IsIssuePoster"] = ctx.IsSigned && issue.IsPoster(ctx.Doer.ID)
 	ctx.Data["HasIssuesOrPullsWritePermission"] = ctx.Repo.CanWriteIssuesOrPulls(issue.IsPull)
diff --git a/templates/repo/diff/comments.tmpl b/templates/repo/diff/comments.tmpl
index 3b8f1c2a9..863e29586 100644
--- a/templates/repo/diff/comments.tmpl
+++ b/templates/repo/diff/comments.tmpl
@@ -37,7 +37,7 @@
 			<div class="comment-header-right actions df ac">
 				{{if and .Review}}
 					{{if eq .Review.Type 0}}
-						<div class="ui label basic small yellow">
+						<div class="ui label basic small yellow pending-label">
 						{{$.root.i18n.Tr "repo.issues.review.pending"}}
 						</div>
 					{{else}}
diff --git a/templates/repo/diff/new_review.tmpl b/templates/repo/diff/new_review.tmpl
index cbaabe255..e4110b50e 100644
--- a/templates/repo/diff/new_review.tmpl
+++ b/templates/repo/diff/new_review.tmpl
@@ -1,6 +1,7 @@
 <div class="ui top right pointing dropdown custom" id="review-box">
 	<div class="ui tiny green button btn-review">
 		{{.i18n.Tr "repo.diff.review"}}
+		<span class="ui small label review-comments-counter" data-pending-comment-number="{{.PendingCodeCommentNumber}}">{{.PendingCodeCommentNumber}}</span>
 		{{svg "octicon-triangle-down" 14 "dropdown icon"}}
 	</div>
 	<div class="menu review-box">
diff --git a/web_src/js/features/repo-diff.js b/web_src/js/features/repo-diff.js
index 45dad52fb..013b8d3fa 100644
--- a/web_src/js/features/repo-diff.js
+++ b/web_src/js/features/repo-diff.js
@@ -6,8 +6,23 @@ import {validateTextareaNonEmpty} from './comp/EasyMDE.js';
 const {csrfToken} = window.config;
 
 export function initRepoDiffReviewButton() {
+  const $reviewBox = $('#review-box');
+  const $counter = $reviewBox.find('.review-comments-counter');
+
   $(document).on('click', 'button[name="is_review"]', (e) => {
-    $(e.target).closest('form').append('<input type="hidden" name="is_review" value="true">');
+    const $form = $(e.target).closest('form');
+    $form.append('<input type="hidden" name="is_review" value="true">');
+
+    // Watch for the form's submit event.
+    $form.on('submit', () => {
+      const num = parseInt($counter.attr('data-pending-comment-number')) + 1 || 1;
+      $counter.attr('data-pending-comment-number', num);
+      $counter.text(num);
+      // Force the browser to reflow the DOM. This is to ensure that the browser replay the animation
+      $reviewBox.removeClass('pulse');
+      $reviewBox.width();
+      $reviewBox.addClass('pulse');
+    });
   });
 }
 
diff --git a/web_src/js/features/repo-issue.js b/web_src/js/features/repo-issue.js
index a39a704f4..4e077c14e 100644
--- a/web_src/js/features/repo-issue.js
+++ b/web_src/js/features/repo-issue.js
@@ -160,6 +160,16 @@ export function initRepoIssueCommentDelete() {
         _csrf: csrfToken,
       }).done(() => {
         const $conversationHolder = $this.closest('.conversation-holder');
+
+        // Check if this was a pending comment.
+        if ($conversationHolder.find('.pending-label').length) {
+          const $counter = $('#review-box .review-comments-counter');
+          let num = parseInt($counter.attr('data-pending-comment-number')) - 1 || 0;
+          num = Math.max(num, 0);
+          $counter.attr('data-pending-comment-number', num);
+          $counter.text(num);
+        }
+
         $(`#${$this.data('comment-id')}`).remove();
         if ($conversationHolder.length && !$conversationHolder.find('.comment').length) {
           const path = $conversationHolder.data('path');
diff --git a/web_src/less/_review.less b/web_src/less/_review.less
index eddd32fa6..8bc41b973 100644
--- a/web_src/less/_review.less
+++ b/web_src/less/_review.less
@@ -242,6 +242,19 @@ a.blob-excerpt:hover {
   border: none !important;
 }
 
+#review-box .review-comments-counter {
+  background-color: var(--color-primary-light-4);
+  color: #fff;
+}
+
+#review-box:hover .review-comments-counter {
+  background-color: var(--color-primary-light-5);
+}
+
+#review-box .review-comments-counter[data-pending-comment-number="0"] {
+  display: none;
+}
+
 .pull.files.diff [id] {
   scroll-margin-top: 99px;
 
diff --git a/web_src/less/animations.less b/web_src/less/animations.less
index 083e10089..92a3052a1 100644
--- a/web_src/less/animations.less
+++ b/web_src/less/animations.less
@@ -50,3 +50,19 @@
     opacity: 0;
   }
 }
+
+@keyframes pulse {
+  0% {
+    transform: scale(1);
+  }
+  50% {
+    transform: scale(1.8);
+  }
+  100% {
+    transform: scale(1);
+  }
+}
+
+.pulse {
+  animation: pulse 2s linear;
+}