Abstract: This sprung seat notably for off-road vehicles is mounted on the vehicle's frame and provided with elastic return means in the form of a hydropneumatic device associated with an automatic monitoring distributor adapted to be connected to the pressure fluid circuit of the vehicle and capable of regulating the fluid pressure in the hydropneumatic device as a function of the seat squab frame oscillation. The hydropneumatic device is constructed to eliminate suction and incorporates an adjustable valve means adapted to be set as a function of the weight of the occupant of the seat.