(E)-N'-[(2-Hy-droxy-naphthalen-1-yl)methyl-idene]-4-methyl-benzene-sulfono-hydrazide.

In the title compound, C(18)H(16)N(2)O(3)S, the dihedral angle between the planes of the benzene ring and the naphthyl ring system is 83.37 (10)°. An intra-molecular O-H⋯N hydrogen bond occurs. Inter-molecular N-H⋯O hydrogen bonds stabilize the crystal structure. There is a π-π inter-action between the naphthyl ring systems [centroid-centroid distance = 3.7556 (15) Å]. In addition, naphth-yl-tolyl and naphth-yl-naphthyl C-H⋯π inter-actions are observed.