The applicability to the screening of crystallization solvents of solubility values estimated by the COSMO-RS (COnductor-like Screening MOdel for Realistic Solvents) method was investigated. The tendencies of estimated and experimental solubility were found to be consistent. When the enthalpy of fusion and melting point were obtained from differential scanning calorimetry (DSC), the minimum error of estimation was about 25%. In comparison, when enthalpy of fusion was calculated from the experimental solubility in a given solvent, the minimum error was reduced to 9%. Thus, it was judged that estimation of solubility by the COSMO-RS method can contribute greatly to the selection of crystallization solvents and the development of crystallization processes.