The authors examine liquid-vapor equilibrium in the binary systems tetraethoxysilane (TEOS)-triethoxyantimony and TEOS-tetraethoxygermanium. Data on liquid-vapor equilibrium in the system TEOS-TEOG and TEOS-triethoxyantimony are presented. The system TEOS-TEOG is ideal over the entire pressure and concentration ranges. The separation factor for this system is in the range 2. 84-3. 14, indicating fairly high efficiency of the distillation method for separation of these substances over the whole range of component concentrations. The system TEOS-triethoxyantimony is not ideal at the concentrations and pressures studied. The values of the activity coefficients calculated from the van Laar equation indicate moderated deviations from ideality in this system.