A stair-climbing wheelchair having wheels defining a first wheel base and a pair of endless, flexible tracks providing a second wheel base, there being a motor-driven structure for moving the tracks into and out of ground-engaging positions. A first pivotal arm is pivotally mounted on the wheelchair near the front end thereof. The first arm is coupled to a fluid piston and cylinder assembly which actuates and cushions the pivotal movement of the arm as the wheelchair moves from a horizontal position to an inclined position, such as moving from the top of a stairway to the slope of the stairway as the wheelchair moves down the stairway. Similarly, a second arm coupled with a fluid piston and cylinder assembly is coupled to the wheelchair to cushion the movement of the wheelchair and its occupant as they move from an inclined position to a generally horizontal position, such as at the top of a stairway.