Nucleation parameters such as critical radius, critical free energy and volume free energy change have been evaluated for L-alanine single crystals. The interfacial energy of the solution at various temperatures has been estimated from existing solubility data. Metastable zone width and induction period measurements have been carried out experimentally. The thermal strength of the grown crystals has also been determined from differential scanning calorimetry (DSC). (C) 2007 Elsevier B.V. All rights reserved.