The current theoretical models for prediction of gas permeation through mixed matrix membranes (MMMs) were studied. The models of Maxwell, Bruggeman, Lewis-Nielsen, Chiew and Glandt and Pal were evaluated. Based on the results, average absolute relative errors (AAREs) of the models are high in prediction of MMMs permeability; for example, AAREs of permeability prediction of CO2 through MMMs composed of incorporated CMS within Matrimid is 26-34% and for O-2 through two MMMs of BAPB-BPADA-zeolite 4A is 25-28% and finally for PVAc-zeolite 4A is 32-34%. These errors are due to the undesirable phenomena such as polymer chain rigidification and total or partial pore blockage in the case of porous inorganic fillers. In this study, the effects of polymer chain rigidification and partial pore blockage were considered and included in ideal models, simultaneously. The common optimized values of alpha (the partial pore blockage factor) and beta (the chain rigidification factor) were calculated for all the models and it was observed that the AARE values are less than 8% for all them. (C) 2012 Elsevier B.V. All rights reserved.