A circumcision instrument used to perform a circumcision procedure. The circumcision instrument generally includes a housing having a chamber configured to receive a glans penis and an outer surface configured to be enveloped by a prepuce. An annular groove is disposed in the outer surface. A conductive ring is located at the bottom of the annular groove. A clamp has a pair of jaws that are moveable from an open position to a closed position surrounding the prepuce. In the closed position the jaws are disposed at least partially within the annular groove. A conductive inner cutting edge is located on the jaws. The clamp and the housing are connectable to a source of diathermy energy such that diathermy energy can flow between the inner cutting edge and the conductive ring, thereby cutting the prepuce.
