Abstract: A resectoscope has a shaft and a lock body which is slidable along the shaft and to which the proximal end portion of a resection electrode can be fixed. A handle is provided for displacing the lock body and thus the electrode along the shaft. The handle consists of a first portion connected to the lock body and projecting radially outwardly of the lock body and a second portion connected to the shaft, for engagement by a thumb of the user of the resectoscope. The first portion of the handle is formed as a disc provided with gripping aids for the user's fingers.