Abstract: A pilfer-proof closure for use in combination with a standard container having a threaded neck portion and a collar below said threaded portion, comprising a body having an internally threaded upper portion followed by a lower skirt portion for protecting a flexible locking member attached to the inside of the body by frangible connectors situated on the outside circumference of the locking member. The locking member extends partially below the skirt portion so that it may be easily viewed. The skirt, however, extends past the frangible connectors to protect the connectors from tampering and severing. The flexible locking member carries a top surface which engages beneath the collar when the closure is threaded onto the container. When the closure is unthreaded from the container, the frangible connecting means are broken to completely disconnect the locking member from the threaded portion of the closure.