An adjustable height seat for a wheelchair has a seat supported on a telescoping support. The seat rises and lowers in response to repositioning of the user's body weight on the seat. A spring normally urges the seat towards an elevated condition. The seat is depressed when the user's body assumes a relatively reclined position to overcome upward urging of the spring. Conversely, the seat rises when the user's body weight is partially rested on a ground surface allowing the spring to lift the seated user's remaining body weight. The telescoping support is frictionally arrested in a generally upright or forward leaning position of the seated user. The adjustable height seat can be installed in a wheelchair frame either permanently or interchangeably with a conventional wheelchair seat.