We report piezoresponse force microscopy (PFM) studies of single electrospun polyvinylidene fluoride (PVDF) nanofibers on the Pt/Ti electrode substrate. The out-of-plane piezoelectric response is much stronger than the in-plane, which is dependent on the parameters of the electrospinning technique. Further, the local polarization switching of the thin nanofibers can be quantitatively characterized by the amplitude-voltage butterfly loop and phase-voltage hysteresis loop. The piezoelectric coefficient (d(33)) of the nanofibers is diameter-dependent. The thinnest nanofiber studied here is 30 nm and has the maximal vertical bar d(33)vertical bar of 38.5 pm V-1. The excellent piezoelectric properties of these low-dimensional nano fibers can facilitate the development in sensing and energy harvesting applications. (C) 2016 Elsevier B.V. All rights reserved.