A sewing machine comprises an upper shaft adapted in a known manner to reciprocate the needle of the sewing machine. A motor-driven pulley is freely turnable on the shaft and normally connected to the latter by a clutch. A stop cam having an engaging face is fixed to the shaft for rotation therewith and a stop lever is movable by a manually operated lever between an inoperative position located out of the path of rotation of the engaging face and an operating position in the path of the latter to stop rotation of the cam and therewith the shaft upon engagement of the stop lever with the engaging face. Elements cooperating with the stop cam cooperate with the clutch to disconnect the pulley from the shaft when the stop lever blocks rotation of the stop cam. Regulating elements cooperate with a cycle stitch control cam driven by the shaft with a predetermined speed to normally hold the stop lever in the inoperatives position and the stitch control cam moves the regulating elements in a direction to release the blocked lever after a predetermined number of revolutions of the shaft.The sewing machine includes further a switch in circuit with the motor driving the pulley and elements cooperating with the manually operated lever for switching off the motor when the stop lever stops rotation of the stop cam, and manually adjustable cams for moving the regulating elements between an inoperative position spaced from the stitch control cam and an operative position engaging the latter.