(E)-N'-(2,4,5-Trimethoxy-benzyl-idene)isonicotinohydrazide dihydrate.

The asymmetric unit of the title compound, C(16)H(17)N(3)O(4)·2H(2)O, contains one Schiff base mol-ecule and two water mol-ecules. The Schiff base mol-ecule exists in an E configuration with respect to the C=N double bond and is essentially planar, the dihedral angle between the benzene and pyridine rings being 5.48†(8)°. The three meth-oxy groups are also coplanar with the benzene ring [C-O-C-C torsion angles = 3.9†(2), 178.51†(15) and 0.8†(2)†à ]. In the crystal structure, the water mol-ecules link the mol-ecules into a three-dimensional network via inter-molecular N-H⋯O, O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds.