<p>We presently applied the Butler equation coupled with a cubic equation of state (CEoS) to accurately represent the surface tension of several representative binary liquid mixtures containing highly polar and associating substances (<i>e.g.</i>, methanol + water, ethanol + water, 1-propanol + water, 2-propanol + water, acetic acid + water, and toluene + methanol) over the entire composition range, at saturation pressure, and within a temperature range of 20–50&#xa0;°C. The main thermodynamic quantities involved in the resulting Butler-based model, namely the fugacity coefficients in the bulk and surface liquid phases, were obtained using the Peng–Robinson-Stryjek-Vera CEoS which was combined with modern mixing rules of the Wong–Sandler type, enabling a proper description of the highly non-idealities exhibited by the binary mixtures considered in this study. The results obtained were generally satisfactory; however, we found out that the performance of the present modeling approach was highly dependent on the choice of the molar surface area of the pure species (<i>A</i>_<i>i</i>) within the Butler framework. Consequently, three diverse modeling scenarios were explored: (1) estimating <i>A</i>_<i>i</i> values using the Paquette correlation, thus making the present model fully predictive; (2) using the recommended <i>A</i>_<i>i</i> values as reported by Suarez et al., also yielding a fully predictive model; and (3) treating the <i>A</i>_<i>i</i> values as adjustable parameters within the present model.</p>