Lead antimonate glasses doped with 1.0 mol% of Er₂O₃ and co-doped with Y₂O₃, Sc₂O₃ and HfO₂ were synthesized. Optical absorption and luminescence spectra of the prepared glasses were recorded at ambient temperature. The spectra were characterized using Judd–Ofelt theory and various radiative parameters viz., transition probability A, branching ratio β and the radiative lifetime τ of principal emission transitions of these glasses have been evaluated. The results indicated a significant enhancement in the intensity of green and orange emissions of Er³⁺ ions due to co-doping of the glass system with Y₂O₃, Sc₂O₃ and HfO₂. The quantitative analysis of the results pointed out that hafnia is the most favorable oxide among the three co-dopants for getting the highest quantum efficiency of green and orange emissions. The results were further analyzed based on the structural modifications taking place in the vicinity of Er³⁺ ions due to co-doping with Y₂O₃, Sc₂O₃ and HfO₂ and the reasons for such improvement have been identified and discussed.