A combination suction and irrigation fluid supply valve assembly includes a first body part with an axial passage and opposed bosses and second and third body parts mounted on the first body part and supporting respective spool type closure members for controlling flow of irrigation fluid and aspiration of fluids through a medical instrument connected to the valve assembly. The fluid supply closure member includes differential areas to provide for fluid pressure biasing of the closure member in a closed position and the suction closure member includes a substantial groove formed therein to provide unobstructed flow of debris laden fluid through the valve assembly. Connector assemblies are connected to the opposed bosses on the body to provide connection to a medical instrument while minimizing unwanted disconnection from the instrument. Circumferentially spaced grooves on one of the connector assemblies are operable to receive a locating pin on the instrument to provide for predetermined orientation of the instrument. Button type actuators are arranged with respect to a hand grip on the valve body to provide ease of handling and operation by either hand of the valve operator.