Abstract: A reciprocating pump having a piston completely enclosed by and moving within a cylinder. The pumping action is provided by the interaction between a magnetic component embedded in the piston and an external varying magnetic field produced by a permanent magnet, solenoid, etc. The necessary back-and-forth motion is produced by momentarily offsetting the gravitational force by the spatial driving or time variation of the magnetic field and a suitable combination of valves is provided to control the fluid flow through the cylinder.