To provide a posture control device for a work vehicle capable of setting a machine body to a proper state with minimum longitudinal tilt without requiring a troublesome manual action at a start or at acceleration or deceleration.

When the acceleration at an advance travel is detected to be a set value or above, the posture is controlled so that the longitudinal tilt posture of the machine body V becomes a set forward tilt posture. When the acceleration at a reverse travel is detected to be a set value or above, the longitudinal tilt posture of the machine body V is changed and controlled to a set backward tilt posture.