An arm for a windshield wiper of automotive vehicles, which rests in its standstill position abutting against the adjacent pillar (7) of the windshield (10) and comprises a frame (2) constituted of a grooved profile which is hinged at one end to the base (1) for connecting to the shaft of the drive motor, according to a shaft (5), and houses the cleaning wiper-blade (4) along the length thereof. The profile (2) has on the wall faceable to the pillar (7) at least one projection (8) through which it rests on said pillar, defining therewith in the resting position a spacing between the grooved profile and the pillar.