The invention relates to a retractable rear-view mirror for motor vehicles. Said rear-view mirror comprises a fixed base, a swiveling mirror unit and a rotation driving unit composed of a motor and a transmission. In order to minimize the friction losses while requiring a minimal space and providing a favorable assembling shape: a) the transmission of the rotation driving unit is a harmonic drive transmission having a central axis which is coaxial with the rotation axis of the mirror unit; b) said voltage wave transmission contains an eccentric means in its transmission casing, an elastic annular gear and two driven links which co-operate with said annular ring and have a different number of teeth; c) the eccentric means has a toothed work which engages the pinion gear of said motor; d) one driven link engages the base and the other driven link engages the mirror unit. The eccentric means is placed inside the elastic annular ring and the two driven links are placed outside of the elastic annular ring. One driven link is integrated to the transmission casing and the other one engages the part which can move relatively to the transmission casing.