Motorized wheelchair (1) for the transportation of at least one sitting person, comprising a supporting frame (2) provided with two side portions (3, 4) each having a plurality of threaded holes (5) present on the inner side (3a, 4a) of both said side portions, a couple of wheels (6, 7) both disposed on the outer side (3b, 4b) of said two side portions (3, 4), a main body (8) provided with a seat (9) and two side walls (10, 11) connectable to said supporting frame between said two side portions, and a device (12) for constraining firmly said main body to said supporting frame, characterized in that said constraining device comprises at least one fixing plate (13) hangable firmly on the inner side (3a； 3b) of least one of said two side portions of said supporting frame, at said plurality of threaded holes, and means for coupling translationally said main body to said fixing plate.
