diff --git a/phpBB/includes/functions_privmsgs.php b/phpBB/includes/functions_privmsgs.php
index ad142b1cca..838c6a0fec 100644
--- a/phpBB/includes/functions_privmsgs.php
+++ b/phpBB/includes/functions_privmsgs.php
@@ -914,6 +914,24 @@ function update_unread_status($unread, $msg_id, $user_id, $folder_id)
 	}
 }
 
+function mark_folder_read($user_id, $folder_id)
+{
+	global $db;
+
+	$sql = 'SELECT msg_id
+		FROM ' . PRIVMSGS_TO_TABLE . '
+		WHERE folder_id = ' . ((int) $folder_id) . '
+			AND user_id = ' . ((int) $user_id) . '
+			AND pm_unread = 1';
+	$result = $db->sql_query($sql);
+
+	while ($row = $db->sql_fetchrow($result))
+	{
+		update_unread_status(true, $row['msg_id'], $user_id, $folder_id);
+	}
+	$db->sql_freeresult($result);
+}
+
 /**
 * Handle all actions possible with marked messages
 */
diff --git a/phpBB/includes/ucp/ucp_pm.php b/phpBB/includes/ucp/ucp_pm.php
index 7a8c694870..425a56cf6c 100644
--- a/phpBB/includes/ucp/ucp_pm.php
+++ b/phpBB/includes/ucp/ucp_pm.php
@@ -45,7 +45,7 @@ class ucp_pm
 
 	function main($id, $mode)
 	{
-		global $user, $template, $phpbb_root_path, $auth, $phpEx, $db, $config;
+		global $user, $template, $phpbb_root_path, $auth, $phpEx, $db, $config, $request;
 
 		if (!$user->data['is_registered'])
 		{
@@ -246,6 +246,27 @@ class ucp_pm
 					$folder_id = (int) $row['folder_id'];
 				}
 
+				if ($request->variable('mark', '') == 'all' && check_link_hash($request->variable('token', ''), 'mark_all_pms_read'))
+				{
+					mark_folder_read($user->data['user_id'], $folder_id);
+
+					meta_refresh(3, $this->u_action);
+					$message = $user->lang['PM_MARK_ALL_READ_SUCCESS'];
+
+					if ($request->is_ajax())
+					{
+						$json_response = new \phpbb\json_response();
+						$json_response->send(array(
+							'MESSAGE_TITLE'	=> $user->lang['INFORMATION'],
+							'MESSAGE_TEXT'	=> $message,
+							'success'		=> true,
+						));
+					}
+					$message .= '<br /><br />' . $user->lang('RETURN_UCP', '<a href="' . $this->u_action . '">', '</a>');
+
+					trigger_error($message);
+				}
+
 				$message_row = array();
 				if ($action == 'view_message' && $msg_id)
 				{
@@ -332,6 +353,7 @@ class ucp_pm
 					'U_SENTBOX'				=> $this->u_action . '&amp;folder=sentbox',
 					'U_CREATE_FOLDER'		=> $this->u_action . '&amp;mode=options',
 					'U_CURRENT_FOLDER'		=> $this->u_action . '&amp;folder=' . $folder_id,
+					'U_MARK_ALL'			=> $this->u_action . '&amp;folder=' . $folder_id . '&amp;mark=all&amp;token=' . generate_link_hash('mark_all_pms_read'),
 
 					'S_IN_INBOX'			=> ($folder_id == PRIVMSGS_INBOX) ? true : false,
 					'S_IN_OUTBOX'			=> ($folder_id == PRIVMSGS_OUTBOX) ? true : false,
diff --git a/phpBB/language/en/ucp.php b/phpBB/language/en/ucp.php
index ad7063d3f9..07751d1f7f 100644
--- a/phpBB/language/en/ucp.php
+++ b/phpBB/language/en/ucp.php
@@ -417,6 +417,8 @@ $lang = array_merge($lang, array(
 	'PM_FROM_REMOVED_AUTHOR'	=> 'This message was sent by a user no longer registered.',
 	'PM_ICON'					=> 'PM icon',
 	'PM_INBOX'					=> 'Inbox',
+	'PM_MARK_ALL_READ'			=> 'Mark all messages read',
+	'PM_MARK_ALL_READ_SUCCESS'	=> 'All private messages in this folder have been marked read',
 	'PM_NO_USERS'				=> 'The requested users to be added do not exist.',
 	'PM_OUTBOX'					=> 'Outbox',
 	'PM_SENTBOX'				=> 'Sent messages',
diff --git a/phpBB/styles/prosilver/template/ucp_pm_message_header.html b/phpBB/styles/prosilver/template/ucp_pm_message_header.html
index d777de908d..7be51e0034 100644
--- a/phpBB/styles/prosilver/template/ucp_pm_message_header.html
+++ b/phpBB/styles/prosilver/template/ucp_pm_message_header.html
@@ -48,6 +48,7 @@
 			<!-- IF S_VIEW_MESSAGE -->
 				<a class="arrow-{S_CONTENT_FLOW_BEGIN}" href="{U_CURRENT_FOLDER}">{L_RETURN_TO_FOLDER}</a>
 			<!-- ELSEIF FOLDER_CUR_MESSAGES neq 0 -->
+				<!-- IF U_MARK_ALL --><a href="{U_MARK_ALL}" class="mark">{L_PM_MARK_ALL_READ}</a> &bull; <!-- ENDIF -->
 				{TOTAL_MESSAGES}
 				<!-- IF .pagination -->
 					<!-- INCLUDE pagination.html -->