An implant tool for use with an endocardial or other implantable lead having an extendable/retractable active fixation tip includes a housing, a shaft rotatably supported by the housing, and a shaft rotation mechanism for rotating the shaft through a predetermined angular travel. The shaft includes a lead attachment portion for selectively coupling a lead to the shaft such that the lead is rotatable with the shaft. The implant tool may include a control tab slidably supported by the housing, wherein longitudinal movement of the control tab actuates the shaft rotation mechanism. The shaft rotation mechanism may include a gear train, an electric motor, a double acting spring mechanism, or a retractable tape wound around the shaft. The gear train includes an input member coupled to the control tab and an output gear coupled to the shaft. The input member meshes with an input gear supported by the housing.