Abstract: An instrument for measuring the depth of a hole in a bone or other tissue electronically, and for providing a convenient display of information relating to the depth. The surgical depth gauge comprises a probe insertable into the hole with an indented hook for positioning the distal end of the probe against a distal surface of the bone, and a reciprocating member slidably connected to the probe and positionable against a proximal surface of the bone. The probe cooperates with a sensor in an electronic circuit connected to the reciprocating member to produce an electronic signal that changes with the distance between the first surface and the second surface. The electronic circuit comprises a power source and a display. The instrument is robust to contamination and sterilization, and is designed for use by both left and right-handed surgeons.