A thumbwheel control assembly operably supported on the handle assembly of a motor powered surgical instrument. The thumbwheel control assembly communicates with a motor in the handle such that when an actuator portion of the thumbwheel control assembly is pivoted in a first direction, the motor applies a rotary motion to one of an elongate shaft assembly and an end effector coupled thereto in the first direction and when the actuator portion is pivoted in a second direction, the motor applies the rotary motion to one of the elongate shaft assembly and end effector in the second direction.