In the present work, the existing theoretical models for the estimation of gas permeation through mixed matrix membranes (MMMs) were tested using the available literature data and the results are discussed in detail. Based on the analysis, the variables affecting the relative permeability of gases have been identified. By incorporating the rigidified interfacial layer between the molecular sieve phase and the polymer phase, a new methodology was developed by using Pal model as a base. The present proposed methodology, showed an accurate prediction of the permeability of gases through different MMMs. The present methodology for the estimation of permeability was validated using the available literature data, and a satisfactory agreement was found. (C) 2011 Elsevier B.V. All rights reserved.