Abstract: A sit down and stand up walker for assisting a user during walking and when not walking in a standing, partially standing or sitting positions with partial or full weight bearing support and with means to change from standing, partially standing to sitting positions with partial weight bearing support to a fixed elevation with full weight bearing support in any varied or repeated sequence. The partial or full weight bearing means supports a seat assembly which includes a seat and front body support with adjustable positioning to provide pelvic stability. The angle of the seat assembly relative to a flat ground surface is maintained at any elevation of the seat assembly between a standing and sitting position. The weight bearing means is responsive to the variable force supplied by the user as the user walks, stands or sits allowing the seat assembly to move up or down.