Flexible piezoelectric generators constructed using one-dimensional nanostructures are well known for their efficient energy harvesting. Herein, we have fabricated a flexible piezoelectric energy harvester (PEH) consisting of a single 0.65Pb(Mg1/3Nb2/3) O-3-0.35PbTiO(3) nanowire (PMN-PT NW) using a facile transferring approach onto a Au electrode-patterned plastic substrate. The well-developed device effectively harvested the maximum output signals (9 mV and 1.5 nA) originating from a single PMN-PT nanowire under mechanical bending/unbending motions. The designed PEH is also expected to be utilized as a versatile tool to evaluate the performance of a one-dimensional nanostructure.