Abstract: A power unit is provided for attachment to a non-motorized golf cart. The power unit converts the cart to a motorized golf cart of the type used to support and carry a golf bag. The power unit includes a motor, drive wheel assembly and battery support, all attached to a single leg which, in turn, is attachable to the frame of the golf cart by means of a releasable coupling which permits the leg to be oriented selectively, at different angles, relative to the golf cart frame. The releasable coupling also allows the leg to be folded against the frame when the cart is collapsed for transport and storage. A pair of relatively closely-spaced drive wheels, mounted on a unitary axle, supports the forward end of the cart and power unit. The drive wheels contact the ground and a reversible motor pushes or pulls the cart in the direction selected by the user. A control box is mounted on the handle of the golf cart to control the speed and direction of the motor.