The title compound 5-[(1H-1,2,4-triazol-1-yl)methyl]-4-(2,3-dimethoxy-benzyli- deneamino)- 2H-1,2,4-triazole-3(4H)-thione monohydrate 4 has been synthesized by the treatment of 4-amino-3-(1,2,4-triazol-1-yl)-1H-1,2,4-triazole-5(4H)-thione 3 with 2,3-dimethoxybenzaldehyde. It crystallizes as a monohydrate in the triclinic system, space group P-1 with a = 8.147(2), b = 10.820(2), c = 10.835(2) (A), α = 73.770(6), β = 84.916(7), γ = 70.679(6)°, C14H17N7O3S, Mr = 363.41, V = 865.4(2) (A)3, Z = 2, Dc = 1.395 g/cm3, F(000) = 380, μ = 0.217 mm-1, the final R = 0.0400 and wR = 0.0975 for 3454 unique reflections. The dihedral angles made by the thione-substituted triazole ring with the other triazole ring and benzene ring are 74.92(3) and 14.81(2)°, respectively. There are some weak hydrogen bonds and C-H…π supramolecular interactions in the lattice, forming a three-dimensional network, which stabilizes the crystal structure.