Gamma-ray mass attenuation coefficients have been measured experimentally and calculated theoretically for PbO–B 2O 3 and Bi 2O 3–PbO–B 2O 3 glass systems using narrow beam transmission method. These values have been used to calculate half value layer (HVL) parameter. These parameters have also been calculated theoretically for some standard radiation shielding concretes at same energies. Effect of replacing lead by bismuth has been analyzed in terms of density, molar volume and mass attenuation coefficient.