In this work, the new definition of the relative molar volume change as recently proposed by de la Fuente Badilla et al. [J. Supercrit. Fluids 17 (2000) 13] has been further investigated. Simulation results show that, according to this new definition, each solvent shows a distinguished molar volume change behavior for a given anti-solvent. In addition, it is shown that the pressure, at which the curve of the relative molar volume change has a minimum, exactly coincides with the pressure at which almost all the solute precipitates in a very narrow pressure window. The results also indicate that the thermodynamically suitable operating temperature should be close, but below the critical temperature of the anti-solvent. Based on these findings, a thermodynamic strategy is proposed to select the proper combination sol vent-anti-solvent for a given solute and the optimum operating conditions as well. (C) 2004 Elsevier B.V. All rights reserved.