A power control unit mounting structure mounted on a vehicle includes an engine in an engine room at a front of the vehicle, an intake manifold disposed above the engine, a power control unit that is disposed above the engine, coupled to a cable, and controls power of a drive motor, and a toeboard cross member disposed on a toeboard. The engine and the toeboard cross member partly overlap in a projected plane along a fore-and-aft direction to provide a space behind the control unit in a front view of the vehicle. The intake manifold and the control unit are disposed within a contour of the engine in a plan view of the vehicle. The intake manifold is disposed ahead of the control unit, and portions of intake pipes of the intake manifold on both sides extend rearward and are partly opposed to both side surfaces of the control unit.