Solubility, metastable zone width and induction period measurements have been performed on bis thiourea zinc acetate (BTZA). Interfacial tension values determined from induction period measurements have been used for evaluation of the nucleation parameters. BTZA crystallizes in the monoclinic structure. The complex formation is stabilized by metal-sulfur coordination. The grown crystal possesses good optical transmission in the entire visible region, which is an essential requirement for nonlinear optical crystals. (c) 2004 Elsevier B.V. All rights reserved.