The r.m.s. deviation from the mean plane for the non-H atoms in the title compound, C(7)H(5)BrN(2)S, is 0.011 Å. In the crystal, the mol-ecules are linked by N-H⋯N and N-H⋯Br hydrogen bonds to generate (010) sheets. Weak aromatic π-π stacking [centroid-to-centroid separation = 3.884 (10) Å] and possible C-H⋯Br inter-actions are also observed. The crystal studied was found to be an inversion twin.