A stand chair is operated by a pair of screw shaft-type linear actuators which extend upwardly and forwardly from a pair of spaced-apart frame members. One embodiment has a solid seat and another has a split seat with a drop-away front portion. One or more motors are provided to operate the screw shafts in such a way as to raise the rear seat portion without changing its angular orientation in space. Connector links interconnect the frame with the front seat portion so as to cause it to drop downwardly out from under the thighs of an occupant, while the back seat portion raises upward, thereby assisting the occupant to stand up and exit the chair. Various additional features such as armrests, wheels and a reclining backrest may also be provided.