Solid-fluid equilibria are important for supercritical fluid processing design. Few data are available, and predictions require a model for the solute-solvent interactions. An activity coefficient model for solids in supercritical CO2, based on linear solvation energy relationships, is developed. The model fits solubility data at liquid-like densities to an average error of 65%. Extrapolations to gas-like densities are shown. (C) 1998 Elsevier Science B.V. All rights reserved.