The correct way of working with transactions is to use: BEGIN ...sql commands COMMIT or ROLLBACK So I would use this for example: pg_connect($connection); pg_query($connection,"BEGIN;"); $insert="INSERT INTO table VALUES (2,7,5); $result=pg_query($connection,$insert); if(!$result){ pg_query($connection,"ROLLBACK"); //Something went wrong with the insert so we rollback and nothing changes in the db }else{ pg_query($connection,"COMMIT"); // If everything went all right, then we commit the changes } pg_close($connection); Of course, the interesting thing comes when you have several operations (inserts, deletes or updates) between begin and commit, this way either you make all the changes or make none, that's the cool thing about transactions. In each operation just check whether the result was valid or not. If ANY of them was invalid, rollback and none of the changes will take effect. I don't know if this answer your question... Adrian Tineo