The invention relates to a drive unit (1) for a wheelchair (2) and a wheelchair (2) comprising such a drive unit (1). The wheelchair (2) comprises control input means (8) and a structural frame (3) with two lateral frame elements (4, 5), each supporting a drive wheel (6, 7). The Drive unit (1) comprises two drive motors (13, 4) mounted within a drive shaft housing (10) and adapted to drive the drive wheels (6, 7)independently of each other based on control input from a driver via the control input means (8). The drive shaft housing (10) is releasably attached between the two lateral frame elements (4, 5) of the wheelchair (2) and connected 10 to the drive wheels (6, 7) via quick-release couplings (11) arranged at each distal end (12) of the drive shaft housing(10). The invention is especially characterized in that the drive shaft housing (10) is divided into at least two sections(A, B), each section housing one of said drive motors(13, 14) and that the at least two sections (A, B) of the drive shaft housing (10) are telescopically moveable relative to each 1 other for adjusting the width (w) of the drive shaft housing (10)to different wheelchairs having different distances between the lateral frame elements (4, 5) of the structural frame (3) of the wheelchair (2).