Based on the nonlocal elasticity theory and Hamilton′s principle, the model for thermo-electro-mechanical vibration analysis was developed for a piezoelectric nanobeam embedded in viscoelastic medium. Governing equations of motion and boundary conditions for vibration analysis were derived where thermo-electro-mechanical loadings, viscoelastic foundation, nonlocal effect and piezoelectric effect were considered simultaneously. The transfer function method was employed to obtain the natural frequencies in closed form for the nanobeam with various boundary conditions. A detailed parametric study was also carried out for the effects of nonlocal parameter, boundary conditions and viscoelastic foundation on the vibration of nanobeams. The study demonstrates the accuracy and the efficiency of the developed model for vibration analysis of a complicated multi-physics system comprising nonlocal piezoelectric nanobeams, viscoelastic foundation and thermo-electro-mechanical loadings.