diff --git a/media/default.css b/media/default.css
index da05765..c3c3432 100644
--- a/media/default.css
+++ b/media/default.css
@@ -103,3 +103,9 @@ table.diff td {
 table.diff tr.annotation td {
     white-space: normal;
 }
+
+.comment-form textarea {
+    display: block;
+    width: 90%;
+    height: 3em;
+}
diff --git a/review/forms.py b/review/forms.py
index ba96e66..d270587 100644
--- a/review/forms.py
+++ b/review/forms.py
@@ -5,3 +5,7 @@ class NewCommitReviewForm(forms.Form):
     author = forms.IntegerField(widget=forms.HiddenInput)
     repo = forms.IntegerField(widget=forms.HiddenInput)
     ref = forms.CharField(widget=forms.HiddenInput)
+class CommentForm(forms.ModelForm):
+    class Meta:
+        model = Comment
+        fields = ('review', 'line_a', 'line_b', 'text')
diff --git a/review/models.py b/review/models.py
index f09468d..310bde2 100755
--- a/review/models.py
+++ b/review/models.py
@@ -40,6 +40,6 @@ class Comment(models.Model):
     author = models.ForeignKey(User)
     created = models.DateTimeField(auto_now_add=True)
     path = models.TextField()
-    line_a = models.IntegerField()
+    line_a = models.IntegerField(null=True)
     line_b = models.IntegerField(null=True)
     text = models.TextField()
diff --git a/review/urls.py b/review/urls.py
index 96f5e45..8baee1c 100644
--- a/review/urls.py
+++ b/review/urls.py
@@ -3,4 +3,5 @@ from django.conf.urls.defaults import *
 urlpatterns = patterns('',
     (r'^(?P<review_id>\d+)/$', 'codereview.review.views.edit'),
     (r'^new/$', 'codereview.review.views.new'),
+    (r'^comment/new/$', 'codereview.review.views.add_comment'),
 )
diff --git a/review/views.py b/review/views.py
index f34ddae..d14ee16 100755
--- a/review/views.py
+++ b/review/views.py
@@ -6,7 +6,7 @@ from django.contrib.auth.decorators import permission_required
 from codereview.browser import vcs
 from codereview.dashboard.models import Repository
 from codereview.review.models import Review, Comment
-from codereview.review.forms import NewCommitReviewForm
+from codereview.review.forms import NewCommitReviewForm, CommentForm
 
 @permission_required('review.add_review')
 def new(request):
@@ -38,3 +38,21 @@ def edit(request, review_id):
         "diffs": diffs,
     })
     return render_to_response('review/edit.html', data)
+@permission_required('review.add_comment')
+def add_comment(request):
+    review_id = request.POST.get('review')
+    try:
+        review = Review.objects.get(pk=review_id)
+        path = int(request.POST.get('path'))
+    except:
+        raise Http404
+    repo = vcs.create(review.repo.type, review.repo.path)
+    diffs = repo.diff(review.ref, review.parent if review.parent else None)
+
+    form = CommentForm(request.POST)
+    comment = form.save(commit=False)
+    diff = diffs[path]
+    comment.author = request.user
+    comment.path = diff.b.path if diff.b else diff.a.path
+    comment.save()
+    return HttpResponseRedirect(reverse(edit, args=[review.pk]))
diff --git a/templates/components/diff.html b/templates/components/diff.html
index 0f5b37f..2e5edb4 100644
--- a/templates/components/diff.html
+++ b/templates/components/diff.html
@@ -12,7 +12,8 @@
                 <td colspan="3">{{ change.text }}</td>
             </tr>
         {% else %}
-            <tr class="{% if change.type == '+' %}add{% endif %}{% if change.type == '-' %}del{% endif %}">
+            <tr id="{{ review.pk }}_{{ forloop.parentloop.counter0 }}_{% if change.type != '+' %}{{ change.line_a }}{% else %}0{% endif %}_{% if change.type != '-' %}{{ change.line_b }}{% else %}0{% endif %}"
+                class="{% if change.type == '+' %}add{% endif %}{% if change.type == '-' %}del{% endif %}">
                 <td class="number">{% if change.type != '+' %}{{ change.line_a }}{% endif %}</td>
                 <td class="number">{% if change.type != '-' %}{{ change.line_b }}{% endif %}</td>
                 <td class="text">{{ change.text }}</td>
diff --git a/templates/review/edit.html b/templates/review/edit.html
index c24cfcc..8d0a7cc 100644
--- a/templates/review/edit.html
+++ b/templates/review/edit.html
@@ -4,6 +4,34 @@
 {% endblock %}
 
 {% block content %}
+<script type="text/javascript">
+    $(document).ready(function() {
+            $('.diff tr:has(.number)').click(function(e) {
+                // Do stuff
+                var form_id = this.id + '_form';
+                var info = this.id.split('_');
+                var path = info[1];
+                var line_a = info[2];
+                var line_b = info[3];
+                if ($('#' + form_id).length == 0) {
+                    // Show the comment form
+                    $(this).after(
+                        '<tr class="comment-form" id="' + form_id + '" ><td colspan="3">' +
+                        '<form method="post" action="{% url codereview.review.views.add_comment %}">' +
+                        "{% csrf_token %}" +
+                        '<input type="hidden" name="review" value="{{ review.pk }}" />' +
+                        '<input type="hidden" name="path" value="' + path + '" />' +
+                        '<input type="hidden" name="line_a" value="' + line_a + '" />' +
+                        '<input type="hidden" name="line_b" value="' + line_b + '" />' +
+                        '<textarea name="text" />' +
+                        '<input type="submit" value="Add Comment" />' +
+                        '<input type="button" value="Cancel" onclick="$(this.form).parent().parent().remove();"/>' +
+                        '</form>' +
+                        '</td></tr>');
+                    }
+            })
+    });
+</script>
 <h2>#{{ review.pk }} - <span id="review-description">{{ review.description }}</span></h2>
 
 {% for diff in diffs %}