diff --git a/isso/js/app/api.js b/isso/js/app/api.js
index 247cfd7..2c5eba5 100644
--- a/isso/js/app/api.js
+++ b/isso/js/app/api.js
@@ -128,19 +128,21 @@ define(["app/lib/promise", "app/globals"], function(Q, globals) {
         return deferred.promise;
     };
 
-    var fetch = function(tid, limit, parent, lastcreated) {
+    var fetch = function(tid, limit, nested_limit, parent, lastcreated) {
         if(typeof(limit) == 'undefined') limit = 0;
+        if(typeof(nested_limit) == 'undefined') nested_limit = 0;
         if(typeof(parent) == 'undefined') parent = null;
         var deferred = Q.defer();
-        curl("GET", endpoint + "/?" + qs({uri: tid || location, limit: limit, parent: parent, after: lastcreated}), null, function(rv) {
-            if (rv.status === 200) {
-                deferred.resolve(JSON.parse(rv.body));
-            } else if (rv.status === 404) {
-                deferred.resolve({total_replies: 0});
-            } else {
-                deferred.reject(rv.body);
-            }
-        });
+        curl("GET", endpoint + "/?" +
+            qs({uri: tid || location, limit: limit, nested_limit: nested_limit, after: lastcreated, parent: parent}), null, function(rv) {
+                if (rv.status === 200) {
+                    deferred.resolve(JSON.parse(rv.body));
+                } else if (rv.status === 404) {
+                    deferred.resolve({total_replies: 0});
+                } else {
+                    deferred.reject(rv.body);
+                }
+            });
         return deferred.promise;
     };
 
diff --git a/isso/js/app/config.js b/isso/js/app/config.js
index a2cc767..d9fa133 100644
--- a/isso/js/app/config.js
+++ b/isso/js/app/config.js
@@ -5,7 +5,8 @@ define(function() {
         "css": true,
         "lang": (navigator.language || navigator.userLanguage).split("-")[0],
         "reply-to-self": false,
-        "max-comments": 20,
+        "max-comments-top": 20,
+        "max-comments-nested": 5,
         "avatar-bg": "#f0f0f0",
         "avatar-fg": ["#9abf88", "#5698c4", "#e279a3", "#9163b6",
                       "#be5168", "#f19670", "#e4bf80", "#447c69"].join(" ")
diff --git a/isso/js/app/isso.js b/isso/js/app/isso.js
index 90c28af..3cc780a 100644
--- a/isso/js/app/isso.js
+++ b/isso/js/app/isso.js
@@ -100,7 +100,10 @@ define(["app/text/html", "app/dom", "app/utils", "app/config", "app/api", "app/m
         $("a.load_hidden", el).toggle("click",
             function() {
                 el.remove();
-                api.fetch($("#isso-thread").getAttribute("data-isso-id"), limit = config["max-comments"], parent=commentWrapper.id, lastcreated=lastcreated).then(
+                api.fetch($("#isso-thread").getAttribute("data-isso-id"), 
+                    limit = config["max-comments-top"], nested_limit=0,
+                    parent=commentWrapper.id, 
+                    lastcreated=lastcreated).then(
                     function(rv) {
                         if (rv.total_replies == 0) {
                             return;
diff --git a/isso/js/embed.js b/isso/js/embed.js
index 11a807a..4bdd98a 100644
--- a/isso/js/embed.js
+++ b/isso/js/embed.js
@@ -26,7 +26,10 @@ require(["app/lib/ready", "app/config", "app/api", "app/isso", "app/count", "app
         $("#isso-thread").append(new isso.Postbox(null));
         $("#isso-thread").append('<div id="isso-root"></div>');
 
-        api.fetch($("#isso-thread").getAttribute("data-isso-id"), limit = config["max-comments"]).then(
+        api.fetch($("#isso-thread").getAttribute("data-isso-id"), 
+            limit = config["max-comments-top"],
+            nested_limit = config["max-comments-nested"],
+            parent='NULL').then(
             function(rv) {
                 if (rv.total_replies == 0) {
                     $("#isso-thread > h4").textContent = Mark.up("{{ i18n-no-comments }}");
diff --git a/isso/views/comments.py b/isso/views/comments.py
index 52d72e6..f172bcd 100644
--- a/isso/views/comments.py
+++ b/isso/views/comments.py
@@ -330,14 +330,20 @@ class API(object):
             try:
                 fetch_args['limit'] = int(request.args.get('limit'))
             except ValueError:
-                return BadRequest("Limit should be integer")
+                return BadRequest("limit should be integer")
         if request.args.get('parent'):
-            try:
-                fetch_args['parent'] = int(request.args.get('parent'))
-                root_id = int(request.args.get('parent'))
-            except ValueError:
-                return BadRequest("Parent should be integer")
+            parent_arg = request.args.get('parent')
+            if parent_arg == 'NULL':
+                fetch_args['parent'] = parent_arg
+                root_id = None
+            else:
+                try:
+                    fetch_args['parent'] = int(parent_arg)
+                    root_id = int(parent_arg)
+                except ValueError:
+                    return BadRequest("parent should be integer or NULL")
         else:
+            fetch_args['parent'] = 'NULL'
             root_id = None
 
         if request.args.get('plain', '0') == '0':
@@ -347,13 +353,20 @@ class API(object):
 
         reply_counts = self.comments.reply_count(uri, after)
 
-        full_list = list(self.comments.fetch(**fetch_args))
-        root_list = [i for i in full_list if i['parent'] == root_id]
+        root_list = list(self.comments.fetch(**fetch_args))
         if not root_list:
             raise NotFound
         if root_id not in reply_counts:
             reply_counts[root_id] = 0
 
+        if request.args.get('nested_limit'):
+            try:
+                nested_limit = int(request.args.get('nested_limit'))
+            except ValueError:
+                return BadRequest("nested_limit should be integer")
+        else:
+            nested_limit = 0
+
         rv = {
             'id'             : root_id,
             'total_replies'  : reply_counts[root_id],
@@ -363,11 +376,17 @@ class API(object):
         # We are only checking for one level deep comments
         if root_id is None:
             for comment in rv['replies']:
-                replies = [i for i in full_list if i['parent'] == comment['id']]
                 if comment['id'] in reply_counts:
                     comment['total_replies'] = reply_counts[comment['id']]
+                    if nested_limit > 0:
+                        fetch_args['parent'] = comment['id']
+                        fetch_args['limit'] = nested_limit
+                        replies = list(self.comments.fetch(**fetch_args))
+                    else:
+                        replies = []
                 else:
                     comment['total_replies'] = 0
+                    replies = []
                 comment['hidden_replies'] = comment['total_replies'] - len(replies)
                 comment['replies'] = self.process_fetched_list(replies, plain)