The title compound, C(6)H(7)N(2)O(2) (+)·Br(-), is isomorphous with 2-nitro-anilinium chloride and contains an characteristic intra-molecular N-H⋯O hydrogen bond, forming an S(6) motif. Inter-molecular N-H⋯Br hydrogen bonds occur in the crystal structure. Two zigzag chains of C(2) (1)(4) motifs extend along the b-axis direction. These primary chain motifs inter-sect like a double helix structure, leading to R(6) (3)(12) ring motifs, which are arranged in tandem along the b axis. Hence, hydro-philic layers are generated at z = 1/4 and 3/4, which are sandwiched between alternate hydro-phobic layers across z = 0 and 1/2.