A new organic nonlinear optical single crystal guanidinium 4-nitrobenzoate (GuNB) was successfully grown by solution growth using the slow evaporation technique. Solubility and metastable zone width were determined for different solvents. The structure of the grown crystal has been determined by single crystal x-ray diffraction analysis. The presence of functional groups and coordination of para nitro benzoate ions in the GuNB crystal have been identified by FTIR and FT Raman spectroscopic studies. The optical transparency range has been studied through UV-vis-NIR spectroscopy. The second harmonic generation efficiency of the grown GuNB crystal has been obtained by the Kurtz-Perry powder technique. The laser induced surface damage threshold for the grown crystal has been measured using Nd: YAG laser. The mechanical behavior has also been studied by Vicker's microhardness test. (C) 2011 Elsevier B.V. All rights reserved.