An image forming apparatus and a power transmission device capable of intermittently transmitting power reliably to a plurality of driven bodies from a driving source with a small number of clutches. The power transmission device includes a cam part which rotates by receiving power of the driving source, a clutch device which intermittently transmits the power to the cam part to determine a stop position of the cam part, a first power transmission unit which transmits the power to any one of the plurality of driven bodies according to the stop position of the cam part, and a second power transmission unit which transmits the power to the other driven bodies of the plurality of driven bodies according to the stop position of the cam part. The cam part includes a rotating disc and a plurality of press members which are provided on one surface of the rotating disc to press the first power transmission unit and the second power transmission unit according to the stop position of the rotating disc.