A river-powered water pump was constructed and tested. The design incorporated a hydrofoil supported by an oscillating arm. An automatic change in the angle of attack of the hydrofoil made the rm rise and fall successively, thus activating a piston pump. With water currents of 0,6 to 1,1 m.s-1 the pump output was 3 to 6 m3 of water per day using a test head of 9 m. The pump should be useful to pump water from highland rivers to adjacent houses.