Abstract: The crystal structure for the hydrochloric acid salt of 4-(2-pyridylazo) resorcinol has been determined from three dimensional X-ray data collected by Syntex P3/R3 four circle diffractometer. The crystal is monoclinic with space group P2₁/c, a = 11.339Å, b = 6.835Å, c = 18.170Å, β= 102.8°and Z = 4. The crystal structure has been solved by Patterson and direct method and refined by block least square refinement with positional parameters, anisotropic temperature and scale factor for nonhydrogen atoms. The final Rfactor is 0.055. The result of crystal structure analysis shows that all the nonhydrogen atoms in the molecule of 4- (2-pyridylazo) resorcinol are coplanar and form an overall conjugate system. The chloride ion and the water molecules in the crystal form hydrogen bonds with the N,Oatoms in molecule and join up the molecules of 4-(2-pyridylazo)resorcinol.