A lockable storage compartment can be mounted in and removed from a medicine cabinet housing in a manner similar to that in which the shelves are mounted and removed. The storage compartment includes a fixed panel and a movable panel. The movable panel is connected to the fixed panel by one or more hinges at the forward edge of the fixed panel and can be swung to open or close the storage compartment. The storage compartment may have a catch that is releasable only from inside the storage compartment for preventing removal of the storage compartment from the medicine cabinet when the storage compartment is closed and locked.