The Peng-Robinson equation of state with quadratic mixing rules and a single adjustable parameter was used to model the solubilities of various high molecular weight solid n-alkanes in supercritical carbon dioxide. The key conclusion of the study is that the adjustable parameter, kij, varies linearly with the number of carbon atoms in the main chain of the n-alkane. Thus, the model can be used to predict the solubilities of various high molecular weight solid n-alkanes in supercritical carbon dioxide. © 2004 Elsevier B.V. All rights reserved.