A viscosity model, based on Eyring's absolute rate theory combined with a cubic PRSV equation of state and G E mixing rule, has been proposed in order to correlate and predict mixture viscosities at atmospheric and high pressure, respectively. In the proposed method, the energy and size parameters in EOS have been obtained using the MHV1 mixing rule combined with the NRTL equation. The NRTL parameters for 22 binary systems have been calculated using viscosity data at atmospheric pressure. The average deviation between the experimental and calculated viscosities is 2.1%. This accuracy is better than the accuracy obtained using the Wong-Sandler mixing rule. The high-pressure viscosities for 10 binary systems have been predicted using NRTL parameters determined and atmospheric pressure viscosity data, and shown to have a deviation of 4.6%.