Cloud-point curves were measured for polystyrene-cyclohexane-gas and polyethylene - cyclohexane-gas systems to determine the influence of the anti-solvent gases ethane, propane and nitrogen on the conditions for LCST-phase separation of these systems. The experimental results and calculations with the SAFT-equation of state suggest that ethane is the most effective among the considered anti-solvent gases for polymer - cyclohexane systems. It is found that the SAFT-equation can be used to correlate the phase equilibria of the investigated polymer-solvent systems and to predict the phase behavior of polymer-solvent-gas systems qualitatively. However, a quantitatively correct prediction of the influence of the addition of supercritical gases on polymer-solvent phase behavior with SAFT is not possible. (C) 2002 Elsevier Science B.V. All rights reserved.