The mol-ecule of the title thia-diazole derivative, C(11)H(11)N(3)O(2)S(2), has a butterfly-like structure and the whole mol-ecule is disordered with a site-occupancy ratio of 0.629 (4):0.371 (4). The mol-ecule is disordered in such a way that the 3-methyl-4-nitro-phenyl units of the major and minor components are approximately related by 180° rotation around the C-N bond axis. The dihedral angle between the 1,3,4-thia-diazole and benzene rings is 70.8 (4)° in the major component and 74.9 (6)° in the minor component. In the crystal, mol-ecules are arranged into screw chains along the c axis. These chains are stacked along the b axis. Weak inter-molecular C-H⋯O and C-H⋯π inter-actions and a short C⋯O contact [3.005 (7) Å] are present.