In the domain for the improvement of acid gas removal technologies from valuable product gas streams by membrane application, this paper discussed gas permeation theoretical models for mixed matrix membranes (MMMs). The models that were considered include Maxwell model, modified Maxwell model, Bruggeman model, Lewis-Nielson model, Pal model, Felske model and modified Felske model. Experimental permeability data on mixed matrix membrane (MMMs) were used to evaluate the selected theoretical models. Comparison of those models based on absolute average relative error percent was conducted. Moreover, present methodology was proposed on modifying Pal model to account for non ideal performance of three phase MMMs and hence minimize the higher deviations obtained by using the original Pal model. The present methodology for the estimation of permeability in MMMs was in a good agreement with experimental literature data. © 2011 IEEE.