A forced ventilation device (1), particularly for road tunnels and the like, comprising an outer casing (2) which has a substantially cylindrical hollow geometric shape, is open at its end faces and can be fixed to the walls of a tunnel and the like by means of a supporting frame (3) in such a manner as to be oriented with its axis of revolution (4) parallel to the longitudinal extension of the tunnel and the like; the device further comprises a drive unit (5) provided with a ventilation impeller (6), arranged inside the outer casing (2) by means of supporting brackets (7) radially protruding therefrom in such a way that the axis of rotation (8) of the ventilation impeller (6) coincides with the axis of revolution (4) of the outer casing (2); the drive unit (5) comprises an outer shell (10) adapted to contain the electromechanical components of the drive unit (5) and having an aerodynamic profile that is such as to facilitate the ventilation of air through the outer casing (2).