Energy harvesting technologies that are engineered to miniature sizes, while increasing the power delivered to wireless electronics [1, 2], portable devices, stretchable electronics  and implantable bio-sensors [4, 5] are strongly desired. Piezoelectric nanowire- and fiber-based generators have potential uses for powering such devices through conversion of mechanical energy into electrical energy . However, the piezoelectric voltage constants of the semiconductor piezoelectric nanowires of the reported nanogenerators [7-12] are low. Here we introduce a piezoelectric nanogenerator based on lead zirconate titanate (PZT) nanofibers . The PZT nanofibers, with diameters and lengths of approximately 60 nm and 500 μm, respectively, were aligned on interdigitated electrodes of platinum fine wires and packaged using a soft polymer on a silicon substrate. The measured output voltage and power under periodic stress applications to the soft polymer were 1.63 V and 0.03 μW, respectively.