The solubility of icariin in water, ethanol, and methanol solutions was measured by UV spectrophotometry from 288.2 K to 328.2 K. The solubility of icariin in the three solvents increased with temperature. Solubility data correlated with a modified Apelblat equation. The enthalpy and entropy of dissolution of icariin were determined using van't Hoff plots. The polarity indices and the surface tension of solvents affect the solubility behaviour. (C) 2012 Elsevier B.V. All rights reserved.