Provided is a power transmission device that can suppress feeling of surprise when power is transmitted and can improve operability while efficiently utilizing a space that is obtained by the arrangement of a first clutch member and a second clutch member. The power transmission device include: a first clutch member 4a that is coupled to an output member 3; a second clutch member 4b to which driven-side clutch plates 7 are attached; a back-torque transmitting cam that is capable of pressing drive-side clutch plates 6 and the driven-side clutch plates 7 against each other by moving the second clutch member 4b when a rotational force is input to the first clutch member 4a; and a cushioning member 12 that is interposed between the first clutch member 4a and the second clutch member 4b and that is capable of applying an urging force while allowing movements of an interlocking member 9 and a pressure member 5 by being compressed in a process in which the interlocking member 9 moves and the pressure member 5 moves from the inactive position toward the active position.