Abstract: A surgical cutter, basically designed for but not limited to laparoscopic surgery, contains a slotted housing and a linearly reciprocating blade which moves parallel to the longitudinal axis of the housing within the slot. The housing also contains a shaped opening near the distal end, the surfaces of this opening being generally perpendicular to the plane of the slot in the housing. Portions of the shaped opening surfaces co-act with the cutting edge of the blade to confine the material to be cut so that it is confined, supported, and cleaved as the blade moves through the plane of the co-acting supporting surface in the opening. The cutting edge of the blade is enveloped by the housing at both ends of the cutting stroke so that the instrument can be safely inserted into and used within the patients body without spurious cutting or damage to the blade.