A power transmission device and an image forming apparatus having the same that is capable of reliably transmitting intermittent power to a driven component from a driving source. The power transmission device includes a shaft, a first intermittent gear to receive power from the driving source and to rotate on the shaft, a second intermittent gear arranged so as to move between a first position in which the second intermittent gear is connected to the first intermittent gear along an axial direction of the shaft and a second position in which the second intermittent gear is disconnected from the first intermittent gear, a sliding unit arranged so as to slide along the shaft and to move the second intermittent gear in the axial direction of the shaft, and a driving unit to drive the sliding unit.