The amino acids 1-threonine, d1-threonine and 1-methionine admixtured triglycine sulfate crystals were grown from aqueous solution by solution growth technique. The cell parameter values were found using powder X-ray diffraction analysis. FTIR analysis was used to estimate qualitatively the presence of the amino acids in the grown crystal. The dielectric studies were carried out to identify the phase transition temperature and to find the dielectric constant. Pyroelectric studies were carried out on the (010) plate and the pyroelectric co-efficient was calculated. Piezoelectric studies were also carried out on the grown crystals. Microhardness studies were carried out using Leitz Weitzler hardness tester at room temperature. (C) 2003 Elsevier B.V. All rights reserved.