An interior rearview mirror for motor vehicles has a mirror support, a mirror housing, and a ball joint having a ball head, wherein mirror housing and the mirror support are connected to one another by the ball joint. At least one electrically operated component is mounted in the mirror housing and has an electrical line connected to a power source for supplying electric current to the at least one electrically operated component. The ball head has at least one slot located laterally in a side of the ball head. The slot allows lateral passage of the electric line into the ball head.