In the routine analysis of osmometric data for polymer-solvent systems, a graphical method has been used to estimate the virial coefficients and number average molar mass. However, it is realized that the graphical method has the disadvantage due to inaccuracies involved in the estimation of the intercept and slope. The least-squares method is certainly a better alternative, but it also has certain limitations. A new analytical method is suggested which is no less effective than the least-squares method, but also provides valuable information about the behaviour of the observed points in the experimental data. A comparative study of the different methods is presented here to indicate the advantages of the new method over the conventional treatments.