New zinc borate glasses of composition 4PbO.2ZnO.5B 2 O 3 . and 2PbO.4ZnO.5B 2 O 3 doped with Pr 3 + , Nd 3 + , Eu 3 + , Dy 3 + , Ho 3 + and Er 3 + were prepared. Absorption and luminescence spectra were measured and the Judd-Ofelt parameters were calculated. The spectroscopic behaviour appears to be strongly influenced by the presence of the highly polarizable Pb 2 + ion. The values of stimulated emission cross sections for selected laser transition appear to be relatively high, suggesting that these materials can be considered as interesting candidates for optical applications.