The crystal structure of the title compound, C(19)H(16)N(2)O(2), displays a trans configuration of the azo moiety, which forms an intramolecular O-H.N=N hydrogen bond. The H.N and O.N distances are 1.81 (3) and 2.581 (4) A, respectively. The azobenzene moiety is approximately planar, and has a dihedral angle of ca 23 degrees with the substituted phenyl group.