A piezoelectrically actuated fluid pump including a pump housing, a pump chamber, inlet and outlet ports for communicating the pump chamber with the exterior of the pump housing, valves for opening and closing the ports, two prestressed piezoelectric diaphragm members which are self-actuated, and a power source is provided. The diaphragm members include a prestressed piezoelectric element which is durable, inexpensive and lightweight as compared with prior diaphragm pumps of comparable discharge capacity, and is actuated via electrical signals from an outside power source. No exterior mechanical parts for driving the diaphragm members are necessary. A modification is disclosed in which a central computer independently controls the phase angle of oscillation of the two diaphragm members, providing precise flow rate control.