2'-hydroxy-3'-methoxy-5'-allyl-4-methylazobenzene was synthesized in two steps: 4-methylbenzenediazonium chloride was prepared by the reaction of 4- methylaniline, HCL and $NaNO_2$, and was then reacted with eugenol to give 2'-hydroxy-3'-methoxy-5'-allyl-4-methylazobenzene. The molecular structure was identified by UV/VIS, IR, 1H-NMR and elemental analysis. The crystal structure was determined as monoclinic by single crystal X-ray diffraction technique. The final R values was found to be 0. 078 for 1065 observed reflections. The structure consists of isolated molecules with van der Waals contacts and the molecule is essentially planar in the solid state. There is a strong intramolecular hydrogen bond in which the hydroxyl group serves as a donor to the N1 atom.