The present invention generally relates to waste containers and, more particularly, relates to a safety locking device for waste containers. The locking device contains a base unit and a pivoting unit pivotally mounted to the base unit. The base unit contains a pinion member, having a cam thereon, non-movably attached to the base member. The pivoting unit includes a lock casing defining a cavity which houses a locking mechanism. The locking mechanism contains a locking member which is pivotally movable between a blocking position to prevent relative movement between the pivoting unit and the base unit, and a release position to permit the relative movement between the pivoting unit and the base unit.