The benzimidazolone residue in the title mol-ecule, C10H9N3O3, is almost planar, with the largest deviation from the mean plane being 0.016 (2) Å for the C atom linked to the nitro group. This plane is nearly perpendicular to the 1-allyl chain as indicated by the C-N-C-C torsion angle of 90.9 (3)°. The fused-ring system makes a dihedral angle of 5.6 (3)° with the nitro group, leading to a synperiplanar conformation. In the crystal, zigzag supra-molecular chains are formed along the a axis by N-H⋯O hydrogen bonds.