This paper examines the nuclear shielding characteristics for two different lead-zinc-tellurite glass systems with the composition of TeO2-Bi2O3 - ZnO-PbO and TeO2-Na2O - ZnO-PbO coded as series A and series B, respectively. Nuclear shielding features of these glasses have been tested in terms of mass attenuation coefficient (mu/rho), half value layer (HVL), removal cross section (Sigma(R)), exposure buildup factor (EBF), effective atomic number (Z(eff)), and mean free path (MFP). The mu/rho values of these systems were generated by Geant4 Monte Carlo simulations over an extended energy range of 0.015-15 MeV. The generated data of mu/rho were confirmed by XCOM calculations. The results show that the nuclear shielding ability of the lead-zinc-tellurite system increases as Bi2O3 content increases in the glasses of series A and as PbO content increases in the glasses of series B. Moreover, the nuclear shielding ability of the current glass systems have been compared with those of some conventional shielding materials and commercial glasses. It can be concluded that the present lead-zinc-tellurite glass systems could be useful to serve as novel shields for nuclear protection applications.