Isothermal vapor-liquid equilibria (VLE) at 318.15 K and molar excess volume V-E at 298.15 K have been measured for liquid propanenitrile or butanenitrile + heptane or + benzene mixtures. The VLE data were reduced using the Redlich-Kister equation, taking into consideration the vapor phase imperfection in terms of the second molar virial coefficients.