In the present work 4,4-dihydroxyazo benzene was synthesized and grown as single crystal (2 x 5 x 10 turn 3) by slow evaporation solution growth technique. The grown crystals were studied by powder and single crystal X-ray diffraction analyses. The vibrational frequencies of the grown crystal were derived from FTIR spectrum. The thermal, optical and mechanical properties were studied. (C) 2003 Elsevier B.V. All rights reserved.