Abstract: A clasp knife has a pivotally mounted blade which can be swung between an operative extended position and a shrouded position within a body and handle using only one hand. The knife incorporates an actuating lever carrying a latching dog which locks the blade to the lever when the blade and the body are swung from the closed position to the open position while a release member is in a locking position. When the body is swung to the extended position while the release member is in the release position, the latching dog is released from the blade and the blade is detained in the body as the body is swung back to the inoperative closed position.