diff --git a/lib/Tmdb/Api/AbstractApi.php b/lib/Tmdb/Api/AbstractApi.php
index 6a8682a1..9dcfd9ff 100644
--- a/lib/Tmdb/Api/AbstractApi.php
+++ b/lib/Tmdb/Api/AbstractApi.php
@@ -87,6 +87,28 @@ public function post($path, $postBody = null, array $parameters = array(), $head
         return $response->json();
     }
 
+    /**
+     * Send a POST request but json_encode the post body in the request
+     *
+     * @param $path
+     * @param null $postBody
+     * @param array $parameters
+     * @param array $headers
+     * @return mixed
+     */
+    public function postJson($path, $postBody = null, array $parameters = array(), $headers = array())
+    {
+        /**
+         * @var Response $response
+         */
+        if (is_array($postBody)) {
+            $postBody = json_encode($postBody);
+        }
+
+        $response = $this->client->getHttpClient()->postJson($path, $postBody, $parameters, $headers);
+        return $response->json();
+    }
+
     /**
      * Send a PUT request
      *
diff --git a/lib/Tmdb/Api/Account.php b/lib/Tmdb/Api/Account.php
index 54f15023..086076c1 100644
--- a/lib/Tmdb/Api/Account.php
+++ b/lib/Tmdb/Api/Account.php
@@ -12,8 +12,6 @@
  */
 namespace Tmdb\Api;
 
-use Tmdb\Exception\NotImplementedException;
-
 class Account
     extends AbstractApi
 {
@@ -62,14 +60,13 @@ public function getFavoriteMovies($accountId, array $parameters = array(), array
      * @param integer $movieId
      * @param boolean $isFavorite
      * @return mixed
-     * @todo refuses to function? review
      */
     public function favorite($accountId, $movieId, $isFavorite = true)
     {
-        return $this->post('account/' . $accountId . '/favorite', json_encode(array(
+        return $this->postJson('account/' . $accountId . '/favorite', array(
             'movie_id' => $movieId,
             'favorite' => $isFavorite
-        )));
+        ));
     }
 
     /**
@@ -105,13 +102,12 @@ public function getMovieWatchlist($accountId, array $parameters = array(), array
      * @param integer $movieId
      * @param boolean $isOnWatchlist
      * @return mixed
-     * @todo refuses to function? review
      */
     public function watchlist($accountId, $movieId, $isOnWatchlist = true)
     {
-        return $this->post('account/' . $accountId . '/movie_watchlist', json_encode(array(
+        return $this->postJson('account/' . $accountId . '/movie_watchlist', array(
             'movie_id' => $movieId,
             'movie_watchlist' => $isOnWatchlist
-        )));
+        ));
     }
 }
diff --git a/lib/Tmdb/Api/Authentication.php b/lib/Tmdb/Api/Authentication.php
index 94ac0cb5..95162e27 100644
--- a/lib/Tmdb/Api/Authentication.php
+++ b/lib/Tmdb/Api/Authentication.php
@@ -80,7 +80,6 @@ public function getNewSession($requestToken)
      *
      * If a guest session is not used for the first time within 24 hours, it will be automatically discarded.
      *
-     * @throws NotImplementedException
      * @return mixed
      */
     public function getNewGuestSession()
diff --git a/lib/Tmdb/Api/Lists.php b/lib/Tmdb/Api/Lists.php
index b9d0db54..e4f81817 100644
--- a/lib/Tmdb/Api/Lists.php
+++ b/lib/Tmdb/Api/Lists.php
@@ -33,12 +33,15 @@ public function getList($list_id, array $parameters = array(), array $headers =
     /**
      * This method lets users create a new list. A valid session id is required.
      *
-     * @throws NotImplementedException
+     * @param string $name
+     * @param string $description
+     * @param array $parameters
+     * @param array $headers
      * @return mixed
      */
-    public function createList()
+    public function createList($name, $description, array $parameters = array(), array $headers = array())
     {
-        throw new NotImplementedException(__METHOD__ . ' has not been implemented yet.');
+        return $this->postJson('list', array('name' => $name, 'description' => $description), $parameters, $headers);
     }
 
     /**
@@ -57,33 +60,35 @@ public function getItemStatus($list_id, array $parameters = array(), array $head
     /**
      * Get the cast information for a specific list id.
      *
-     * @throws NotImplementedException
+     * @param integer $id
+     * @param string $mediaId
      * @return mixed
      */
-    public function addMediaToList()
+    public function addMediaToList($id, $mediaId)
     {
-        throw new NotImplementedException(__METHOD__ . ' has not been implemented yet.');
+        return $this->postJson('list/' . $id . '/add_item', array('media_id' => $mediaId));
     }
 
     /**
      * Get the images (posters and backdrops) for a specific list id.
      *
-     * @throws NotImplementedException
+     * @param integer $id
+     * @param string $mediaId
      * @return mixed
      */
-    public function removeMediaFromList()
+    public function removeMediaFromList($id, $mediaId)
     {
-        throw new NotImplementedException(__METHOD__ . ' has not been implemented yet.');
+        return $this->postJson('list/' . $id . '/remove_item', array('media_id' => $mediaId));
     }
 
     /**
      * Get the plot keywords for a specific list id.
      *
-     * @throws NotImplementedException
+     * @param integer $id
      * @return mixed
      */
-    public function deleteList()
+    public function deleteList($id)
     {
-        throw new NotImplementedException(__METHOD__ . ' has not been implemented yet.');
+        return $this->delete('list/' . $id);
     }
 }
diff --git a/lib/Tmdb/Api/Movies.php b/lib/Tmdb/Api/Movies.php
index c1e90fab..cb7667c2 100644
--- a/lib/Tmdb/Api/Movies.php
+++ b/lib/Tmdb/Api/Movies.php
@@ -254,6 +254,6 @@ public function getAccountStates($id)
      */
     public function rateMovie($id, $rating)
     {
-        return $this->post('movie/' . $id . '/rating', json_encode(array('value' => (float) $rating)));
+        return $this->postJson('movie/' . $id . '/rating', array('value' => (float) $rating));
     }
 }
diff --git a/lib/Tmdb/HttpClient/HttpClient.php b/lib/Tmdb/HttpClient/HttpClient.php
index 5eab9c77..66009723 100644
--- a/lib/Tmdb/HttpClient/HttpClient.php
+++ b/lib/Tmdb/HttpClient/HttpClient.php
@@ -110,6 +110,18 @@ public function post($path, $postBody, array $parameters = array(), array $heade
         );
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function postJson($path, $postBody, array $parameters = array(), array $headers = array())
+    {
+        $parameters = $this->buildQueryParameters($parameters);
+        $request    = $this->client->post($path, $headers, null, $parameters);
+        $request->setBody($postBody, 'application/json');
+
+        return $this->request($request);
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/lib/Tmdb/HttpClient/HttpClientInterface.php b/lib/Tmdb/HttpClient/HttpClientInterface.php
index f844d1f0..7b8b6e9b 100644
--- a/lib/Tmdb/HttpClient/HttpClientInterface.php
+++ b/lib/Tmdb/HttpClient/HttpClientInterface.php
@@ -41,6 +41,18 @@ public function get($path, array $parameters = array(), array $headers = array()
      */
     public function post($path, $postBody, array $parameters = array(), array $headers = array());
 
+    /**
+     * Compose a POST request but json_encode the body
+     *
+     * @param  string $path       Request path
+     * @param  array  $postBody   The post BODY
+     * @param  array  $parameters POST Parameters
+     * @param  array  $headers    Reconfigure the request headers for this call only
+     *
+     * @return Response              Data
+     */
+    public function postJson($path, $postBody, array $parameters = array(), array $headers = array());
+
     /**
      * Compose a PATCH request
      *