A head restraint for rear seats of convertibles is attached to a U-shaped roll-over bar and can be displaced with the roll-over bar. The roll-over bar can be raised from a lowered position into a support position and spans to a large extent the width of the interior of the vehicle. The lateral legs of the roll-over bar are equally curved along a rear wall of the rear seat rest with a center of curvature on the seat side of the rear seat rest.