The crystal structures of two new compounds were determined: 4-ethyl-3-(4-methyl-1,2,3-thiadiazol-5-y1)-s-triazole-5-thione (1), P2(1)/n, a = 10.433(2), b = 7.975(2), c = 13.100(3) angstrom, beta = 110.70(3)degrees and 4-carboxymethyl-3-(4-methyl-1,2,3-thiadiazol-5-y1)-s-triazole-5-thione (2), P2(1)/c, a = 6.444(1), b = 14.721(3), c = 11.067(2) angstrom, beta = 93.50(3)degrees. In both structures, the molecules form hydrogen-bonded dimers through Nl-H1n center dot center dot center dot S 1 (triazole center dot center dot center dot S=C-triazole) interactions. The crystal structure of is further stabilized by intermolecular C-H center dot center dot center dot N and S center dot center dot center dot S interactions, while in 2, C-H center dot center dot center dot N/O, O-H center dot center dot center dot N/S, S center dot center dot center dot S/O and pi center dot center dot center dot pi It interactions are observed.