An optical trocar assembly has an elongated tubular member for receiving an endoscope which defines a longitudinal axis and has an open proximal end and a closed, optically clear distal end which is adapted for penetrating body tissue. The optical trocar assembly has a handle releasably connected to the elongated tubular member and which defines a passage which is coaxial with the longitudinal axis and which has a distal portion and proximal portion. The distal portion receives the open proximal end and the proximal portion defines a tapering opening. A locking collet is positioned within the tapering opening having a through bore which is coaxial with the longitudinal axis and the tapering external surface. One of the tapering opening and the tapering external surface has a helical rib and the other of the tapering opening and the tapering external surface defines a helical recess engaging the helical rib
