New measurements of the excess molar enthalpy H-m(E) for {yC(2)H(5)OH + (1 - y)C6H6)(g) and {yC(2)H(5)OH + (1 - y)C6H12}(g) measured at standard atmospheric pressure over the temperature range 363.2 K to 433.2 K are reported. These measurements supplement earlier measurements made over the range 453.5 K to 522.9 K at pressures up to 4.5 MPa. The non-ideality of the ethanol vapour is described using a quasi-chemical model in which only dimer and tetramer association equilibria are considered. The values of H-m(E) for (ethanol + cyclohexane)(g) were found to agree well with values calculated using the association model. For (ethanol + benzene)(g) the experimental values of H-m(E) were found to be approximately 20 per cent smaller than values calculated from the model and this was attributed to weak association between the unlike molecules. A quasi-chemical model used to describe the association between the unlike molecules yielded a value of the equilibrium constant K-12(298.15 K) = 0.28 MPa-1 and a value for the enthalpy of the ethanol-benzine association of Delta H-12 = -14 kJ . mol(-1). Second virial cross-coefficients B-12 for ethanol-cyclohexane and ethanol-benzene have been derived from the H-m(E) measurements.