diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 8f15d8d..05e5418 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -381,9 +381,19 @@
 	 */
 	public function error()
 	{
-		$query = $this->query('SELECT @@ERROR AS code');
-		$query = $query->row();
-		return array('code' => $query->code, 'message' => mssql_get_last_message());
+		// We need this because the error info is discarded by the
+		// server the first time you request it, and query() already
+		// calls error() once for logging purposes when a query fails.
+		static $error = array('code' => 0, 'message' => NULL);
+
+		$message = mssql_get_last_message();
+		if ( ! empty($message))
+		{
+			$error['code']    = $this->query('SELECT @@ERROR AS code')->row()->code;
+			$error['message'] = $message;
+		}
+
+		return $error;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index e4250a4..31e0b31 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -30,6 +30,7 @@
 -  Fixed a bug (#4105) - :doc:`Form Validation Library <libraries/form_validation>` didn't allow pipe characters inside "bracket parameters" when using a string ruleset.
 -  Fixed a bug (#4109) - :doc:`Routing <general/routing>` to *default_controller* didn't work when *enable_query_strings* is set to TRUE.
 -  Fixed a bug (#4044) - :doc:`Cache Library <libraries/caching>` 'redis' driver didn't catch ``RedisException`` that could be thrown during authentication.
+-  Fixed a bug (#4120) - :doc:`Database <database/index>` method ``error()`` didn't return error info when called after ``query()`` with the 'mssql' driver.
 
 Version 3.0.1
 =============