The mixed Langmuir adsorption isotherm has been modified for improved prediction of binary gas mixture adsorption equilibria. The modified method has been applied to predict adsorption equilibria for 52 binary gaseous mixtures on adsorbents like activated carbon, silica gel, and carbon and zeolite molecular sieves for which experimental data are reported in the literature. Predictions by this method are generally better for the binary gas mixtures in systems involving activated carbons, silica gel, and carbon molecular sieve adsorbents compared to that of the mixed Langmuir approach. However, in systems having zeolite molecular sieve adsorbents, predictions are less satisfactory. The higher deviations of predicted data from experimental values in these systems are attributed to the lack of single component adsorption isotherm data at low coverages.