Isobaric vapor-liquid equilibria (VLE) were measured with a small Swietoslawsky still for dichlorodimethylsilane + heptane. The measurements were made at atmospheric pressure. Activity coefficients were calculated after accounting for the nonideality of the vapor phase, using calculated virial coefficients. The vapor pressures of the pure components were obtained using Antoine constants from the literature. The results obtained were correlated in terms of liquid activity coefficients calculated from the Wilson, NRTL, and Gothard equations.