A drilling and/or hammering tool which includes a hollow spindle (1) and a tool holder (10) that can be attached to an end (18) of the spindle and removed therefrom. The toll holder comprises a tool holder body (14) which can be fitted within the end of the spindle and releaseably locked therein by means of at least one locking element (32) and a locking ring (42) for releasably holding the or each locking element in a locked position in which the locking element(s) lock(s) the tool holder to the spindle. The tool holder (10) comprises a manually actuable sleeve (40) for rotating the locking ring (42) in a first direction and for rotating the tool holder body (14) in a second opposite direction, and resilient means (62) for urging the tool holder body to follow the movement of the locking ring in the first direction and the locking ring to follow the movement of the tool holder body in the second direction. The resilient means urges the locking ring and the tool holder body into relative rotational positions in which the locking ring (42) holds the or each locking element in the locked position. The locking ring (42) has an internal radius that varies along its circumference so that rotation of the locking ring about the axis of the tool holder body will move it between a locking position in which it causes the or each locking element (32) to retain the toll holder body in the spindle, and a release position in which it will allow the or each locking element to move radially to release the tool holder body.