A cantilever brake for a bicycle includes a pair of bolts each having a threaded portion engaged removably in the threaded bore of one of a pair of cantilever mounting bases fixed to a bicycle frame, a shank which is larger in diameter than its threaded portion, and a head which is larger in diameter than its shank. A pair of spring adjusting members are provided each fitted rotatably about the threaded portion of one of the bolts, and held by and between those end surfaces of the shank of the one bolt and of one of the cantilever mounting bases which face each other. A pair of cantilevers are provided each fitted rotatably about the shank of one of the bolts, and including a boss having a recess which is open towards one of the spring adjusting members. A pair of return springs are provided each housed in the recess of the boss of one of the cantilevers, and having one end engaging the boss of the one cantilever and another end engaging one of the spring adjusting members.