Organic nonlinear optical material diglycinyl thiourea (DGT) has been synthesized and single crystals have been grown from the aqueous solution by solvent evaporation technique. Powder second harmonic generation (SHG) study shows that DGT is 2.5 times efficient than KDP and is phase matchable. The third-order nonlinear optical and optical limiting properties of DGT have been investigated using a 532 nm second harmonics of diode-pumped Nd: YAG laser (1064 nm, 50 mW). The magnitude of nonlinear refractive index, nonlinear absorption coefficient and third-order susceptibility was found to be in the order of 10 (8) cm(2)/W, 10 (3) cm/W and 10 (6) esu, respectively. (C) 2010 Elsevier B. V. All rights reserved.