The surface tension of n-pentane, n-heptane and some of their mixtures were measured at 91.3 kPa and T = (283.15 to 323.15) K by the maximum bubble pressure method. The surface tension results were correlated by a new model obtained from coupling scaled particle theory (SPT) and the MMM equation of state. The parameters of the model (SPTM3) for n-pentane and n-heptane were calculated and reported. The pure component parameters obtained for the model were used for calculating the surface tension of n-pentane and n-heptane binary mixtures at different temperatures. The comparison between the mixture surface tension results and those calculated by the model indicate that the new proposed model can be satisfactorily used for calculating the surface tension of n-pentane, n-heptane and their mixtures. (C) 2009 Elsevier Ltd. All rights reserved.