This paper reports on energy harvesting from an impact by using a piezoelectric MEMS scavenger. Useful electrical power is generated by the impact of the rotating gear on the MEMS piezoelectric transducer. The design of the device structure was based on both analytical and FEM models for the estimation of induced voltage generated from piezoelectric transducer. A prototyping of piezoelectric MEMS based impact harvester consisting of a piezoelectric unimorph transducer was operated on a gearbox with a speed of 25 rpm. For the cantilever type harvester occupying approximately 4.2 mm3, an average output power of 1.26 μW was measured across a resistive load of 2.7 MΩ.