A transmission includes a gear train, a transmission shaft driven by the gear train, a transmission casing incorporating the gear train and the transmission shaft, an axle driven by the gear train, a power take-off (PTO) unit attached to the transmission casing, and a parking brake. The transmission shaft and the axle are extended parallel to each other. The PTO unit includes a PTO input shaft, a PTO shaft, and a PTO drive train transmitting power from the PTO input shaft to the PTO shaft. The PTO input shaft is connected coaxially to the transmission shaft so as to receive power from the transmission shaft. The parking brake is provided on the transmission shaft or the PTO input shaft.