Abstract Molar volumes of mixtures are calculated using the Patel-Teja equation of state. Equations for the partial molar volume (V¯i) and for the partial volume at infinite dilution (V¯i ∞) are obtained from that equation. Partial molar volumes of several mixtures containing Carbon Dioxide are calculated and compared with experimental data. The effect of the interaction parameter (as calculated from vapor-liquid equilibrium data) on the calculation of partial molar volume is also discussed. Volumes at infinite dilution for several solutes in different type of solvents are also calculated using the obtained equations. It is concluded that the Patel-Teja equation is appropriate for the calculation of mixture volumes, of partial molar volumes, and of partial molar volumes at infinite dilution. For non-polar mixtures no interaction parameter is needed while for mixtures containing polar fluids an adjustable interaction parameter is required.