Rail for power window devices for motor vehicles

The rail (1) comprises a section member having a lower fastening portion (3) and an upper fastening portion (2) for engaging said section member to the door (4) and comprising a fastening support (5) having at least a length (6) fixed to the rail (1), a length (7) fixed to the vehicle door (4) and an intermediate length (8) substantially sloped relative to the vertical. The fastening support (5) may be made deformable for adjusting the lower fastening portion (3) of the rail (1) once position thereof has been fixed in said upper fastening portion (2). The invention provides an elastic and resistant fastening of the rail (1) allowing for the balance of the vertical operating loads.