In the title compound, C16H10N4O2·0.17H2O, prepared by the one-step condensation reaction of isatin with hydrazine hydrate under microwave irradiation, the complete organic mol-ecule is generated by crystallographic inversion symmetry and therefore exists in an S-trans conformation. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, generating a three-dimensional framework with [001] channels, which are occupied by the disordered water mol-ecules.