Abstract: A turret tool rest (10) including a tool slide (20), a tool rest body (22) movable on the tool slide, a turret (26) rotatable on the tool rest body and for mounting tools (24) at angularly-indexed positions, a servomotor (30) for rotating the turret, a clutch (32) for releasably connecting the turret with the servomotor, an engaging unit (36) for releasably engaging the turret, and a power transmission device (38) for transmitting output of the servomotor to engaging unit. A drive mechanism (34) for operating the clutch includes an interlocking device (72) operative in association with the movement of the tool rest body on the tool slide so that when the engaging unit is disengaged, the clutch is engaged and the turret is rotatably indexed by the servomotor. When the clutch unit is released, the engaging unit is engaged by operation of the servomotor and the turret is secured at an indexed position on the tool rest body.