A valve timing adjusting apparatus adjusts valve timing of at least one of intake and exhaust valves of an engine that are opened and closed by a camshaft driven by torque transmitted from a crankshaft. The apparatus includes an electric motor, a plurality of switching elements, a motor driver, and a phase adjusting mechanism. When a target rotational direction of a motor shaft of the electric motor is coincident with the actual rotational direction of the same, the motor driver continuously turns on a selected one of the switching elements for the whole of a predetermined rotation angle range of the motor shaft. When the target rotational direction is opposite to the actual rotational direction, the motor driver continuously turns on the selected switching element only for part of the rotation angle range, and continuously turns off the selected switching element for the remaining part of the rotation angle range.