Good-quality novel single crystal of tri-nitrophenol p-hydroxyacetophenone has been successfully grown from aqueous solution by slow evaporation technique. This crystal crystallizes in the monoclinic system with space group P2(1)/c. The NLO test carried out on the sample confirms the existence of nonlinearity in the third harmonic generation. Functional groups of the grown crystal were confirmed qualitatively by infrared spectral analysis. Optical absorption studies on this sample reveal the minimum absorption region, which is well suited for optical applications. Thermal analysis shows that the sample is thermally stable up to 135 degrees C. (C) 2008 Elsevier B.V. All rights reserved.