Abstract: An improved molten metal pump and gas injection apparatus comprising a submersible pump housing 10 enclosing a rotatable impeller 30, an impeller drive 12 supported above the housing and an elongate drive shaft 16 operatively connected to the impeller. Rotation of the drive shaft effects fluid flow between a pump inlet 35 and a pump outlet 44 both being at least partially defined by the impeller housing. A gas injection conduit 54 extends downwardly from a drive motor support platform 20 and includes an output end 54a that terminates near the pump inlet and which is received by a gas inlet collar 58 that defines a venturi 60, coaxial with the axis of the pump inlet. A passage 62 formed in the collar communicates the end of the gas injection conduit with the throat of the venturi so that the gas is injected into the incoming molten metal in an area of low pressure, thereby reducing the gas pressure needed to effect injection.