In this study, Tb-doped PbTe nanoparticles with variable Tb3+ content were synthesized by a simple hydrothermal technique. The synthesized nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). The XRD patterns indicated that the particles were excellently crystallized due to the cubic PbTe phase. The SEM images certify that the substitution of Tb into the lattice of PbTe does not change the morphology of PbTe nanoparticles. The SEM images displayed that the size of the particles was in the range of 25-80 nm. The energy of the bandgap of doped-PbTe and PbTe nanoparticles expected from the chief absorption edges of the UV-Vis diffuse reflectance spectrum. Blue shifts in DRS spectra of PbTe were noticed by increasing the concentration of the Tb3+ ions. The incorporation of Tb3+ into the PbTe lattice was confirmed by the XPS technique. The electrical conductance of various Tb-doped PbTe samples is higher than that for the pure PbTe, and elevates with temperature.