An automatic dispenser assembly is disclosed. The dispenser assembly is adapted to use a replaceable fluid container having a foam pump. The dispenser assembly includes an adapter for securing and positioning a foam pump in the dispenser assembly. The dispenser assembly also includes an actuating mechanism to automatically actuate the foam pump and a control circuit to control the operation of the actuating mechanism. When a sensor assembly detects a hand or other object in the proximity of the dispenser assembly in a position to receive a dose of foam, the actuating mechanism and the control circuit cooperate to drive the foam pump so as to create foam and to return the foam pump to a closed position that prevents leakage.