A new donor-acceptor type of thiourea metal complex, tristhiourea cadmium sulphate (TTCS) was synthesized through chemical reaction method. Structural and linear optical properties have been measured by XRD, FTIR and UV-Vis techniques. From the XRD analysis, TTCS crystallizes in centrosymmetric space group P (1) over bar. There is a bathochromic shift in the absorption edge for ethanol compared to water. By the open aperture Z-scan technique (Nd:YAG, 532 nm, 5 ns), the nonlinearity coefficient (beta) is measured as 4.1 x 10 (11) m/W, which arises from an effective two-photon absorption phenomenon. The resulting optical limiting behavior has a threshold fluence value of 1.5 x 10(4) J/m(2). (C) 2009 Elsevier B.V. All rights reserved.