A generalized cubic equation of state proposed by one of the authors has been applied to the calculation of vapour-liquid equilibrium (VLE) of hydrogen sulfide-containing systems. Experimental VLE data for hydrogen sulfide + hydrocarbons, taken from the literature, have been systematically studied using the generalized equation and conventional van der Waal＇s mixing rules. The interaction parameter required in the mixing rules was obtained for thirteen systems at different temperatures, and a correlation for the interaction parameter as a function of the reduced temperature of the hydrocarbon solvent is proposed. The correlation for the interaction parameter is recommended for predicting VLE in processes in which hydrogen sulfide mixtures are involved.