Abstract: A trocar type biopsy instrument characterized by:(a) structure for locking the cannula and stylet of the instrument together so as to allow these components to penetrate soft body jointly as a unitary whole;(b) structure for retracting the cannula rearward along the stylet far enough to expose the specimen notch, and for returning the cannula along the stylet to its original advanced position covering the specimen notch;(c) removable stylet retaining structure so that the stylet may be removed while the cannula remains locked in its advanced position.The instrument of the present invention facilitates the manipulative efforts required for performing soft tissue biopsy procedures.