Abstract: A cabinet includes a locking mechanism which prevents removal of a key unless the cabinet door is properly closed and a prescribed item is properly positioned and stored within the cabinet. In a preferred embodiment, the cabinet door assembly includes a hinge which is slotted so as to accept a rotatable cam of the locking mechanism to prevent hinge movement in the locked position. The stored item has a magnet secured thereto which, when properly positioned in the cabinet, pulls a spring biased magnetized bar into a position wherein a slotted extension of the bar permits the cam to pass into the hinge slot. With the item improperly positioned or removed, the slotted bar extension prevents rotation of the lock by blocking passage of the cam into the hinge slot. The key and lock combination are standard items of the type which prevent key removal from the lock unless the lock is turned to the locked position.