In this study based on the Soave-Redlich-Kwong equation of state (SRK EOS), a new viscosity model for light hydrocarbons, CO2 and N-2 has been proposed. The proposed model can be applied in both liquid and gas phases and in high and low ranges of pressure and temperature. The optimal values of the parameters in the proposed model are determined by using the Genetic algorithm and generalized in term of acentric factor. The performance of the proposed model has been compared with the performance of Peng-Robinson EOS-based viscosity model of Guo et al. (2001), the Peng-Robinson EOS-based viscosity model of Fan and Wang (2006) and the Lohrenz-Bray-Clark (LBC) method. In order to have a fair comparison, the binary interaction coefficients in the mixing rules are set to zero. The results of calculations for seventeen pure components (6449 data), thirty eight binary mixtures (2772 data), ten simple and twenty complex mixtures (74 data) show the superiority of the proposed model compared to the other viscosity models. (C) 2017 Published by Elsevier B.V.