A backrest (1) for a wheelchair comprising a backrest plate (2), for supporting the backrest of a user using said wheelchair and provided with a main axis X-X, a backrest frame (7), for holding said backrest plate, having two substantially parallel bars extending along said X-X axis, at least one lateral trunk support (4) for laterally holding the trunk of said wheelchair user and provided with trunk support arms, attachment members (3), for attaching said backrest plate to said frame, said backrest plate (2) being provided with at least two longitudinal adjustment slots (6) extending on the side portions of said backrest plate (2) substantially parallel to said backrest main axis X-X, and at least one pair of backrest attachment members (3) being slidably mounted on said slots (2), enabling height adjustment of said backrest plate (2) on said frame (7), the lateral trunk support (4) being also slidably mounted on said slots (2).
