A method for correlating the interaction parameters involved in the UNIQUAC equation has been investigated for binary alkane/alkane systems. Infinite dilution activity coefficients for long-chain alkanes diluted in short-chain alkanes were determined from constant-temperature VLE data using the Wohl equations and the correlation equation of the infinite dilution activity coefficients of the short-chain alkanes. The interaction parameters have been formulated as the functions of the temperature and the system parameters representing the solute and the solvent properties. Using these correlation equations, the Wohl equations accurately predict constant-temperature VLE for the alkane/alkane binaries. (C) 2004 Elsevier B.V. All rights reserved.