Thiourea-doped Triglycine sulphate (ThTGS) crystal with three different concentrations of thiourea was grown from aqueous solution by slow cooling technique. The cell parameters were determined from powder X-ray diffraction analysis. A qualitative analysis of the presence of thiourea in doped crystals was estimated by FTIR analysis. Microhardness studies were carried out using Leitz Weitzler hardness tester at room temperature. Dielectric properties of the crystals were studied which showed a shift in the T-c when compared to pure TGS crystal. Pyroelectric studies were carried out and the pyroelectric coefficient was found. Piezoelectric studies (d(33) coefficient) has also been carried out. (C) 2003 Elsevier B.V. All rights reserved.