In this work vehicle, a control unit controls a shift in a speed gear of a transmission according to the vehicle velocity. The control unit determines whether or not the acceleration rate of the vehicle is equal to or less than a predetermined threshold when the vehicle velocity is within a predetermined first range. The control unit switches a lock-up clutch from a not-connected state to a connected state when the acceleration rate of the vehicle is equal to or less than the predetermined threshold. The control unit maintains the lock-up clutch in a not-connected state when the acceleration rate of the vehicle is greater than the predetermined threshold.