The osmotic coefficients of calcium chloride and calcium nitrate in methanol have been measured by the isopiestic method at the temperature 298.15 K. Sodium iodide served as isopiestic standard for the calculation of osmotic coefficients. The Pitzer model and the self-consistent local composition (SCLC) model developed by Ananth and Ramachandran was used to fit each set of osmotic coefficients. The parameters from the fit were used to calculate the vapor pressures. The osmotic coefficient data are successfully correlated with these models, which provide reliable predictions of vapor pressures.