The backrest for motorcyclists includes a base plate with a pivoting and telescoping strut extending from its forward end. The upper end of the strut has a cushioned seatback pivotally attached thereto. The strut is adjustable to optimize the seatback height. The fore and aft angle of the strut, and thus the angular position of the seatback, is adjusted by an adjustable stop at the base of the strut. The stop limits the rearward angular motion of the strut, but allows the strut to pivot forward against the seating surface to facilitate mounting and dismounting of the motorcycle. The base plate is removably secured to the seat by lateral straps that hook beneath the edges of the seat. The span of the straps may be adjusted by laterally telescoping strap brackets extending from the plate. The bottom of the plate is coated with a non-slip material for greater security.