In a preferred embodiment, a drawer detachably-mountable locking device of simple construction and operation, for securing a closed drawer against opening by a child of younger years thereby avoiding safety hazards against a young child getting to dangerous items such as knives, scissors, drugs, poison cleaners, needles, and the like, a preferred device being a cabinatestructure clamp vise-clampable onto the flange over the opendrawer cabinate, with an extension extending forwardly beyond the front of the closed drawer, the extended portion including a keyreceiving aperture, and a drawer-wedge locking element pressable against the front of the closed drawer, the extended portion including a key-receiving aperture, and a drawer-wedge locking element pressable against the front of the closed drawer and when in that position being key-projection-lockably insertable into the aperture thereby locking the drawer in the closed state, the inserted state being preferably turn-key-securable to prevent removal of the inserted locking key-projection.