A power transmission device that includes a transmission including a plurality of engagement elements for transmitting power from a motor to axles; a case to accommodate the transmission; a hydraulic control device to control hydraulic pressure to the engagement elements; a hydraulic oil reservoir that stores hydraulic oil; and a first pump that is operated by the power from the motor and that suctions the hydraulic oil from the hydraulic oil reservoir through a strainer and supplies the hydraulic oil to the hydraulic control device.