In the title gem-dinitro-azetidinium chloride salt, C3H6N3O4(+)·Cl(-), the cations and anions lie on a mirror plane. The azetidine ring is virtually planar, with a mean deviation from the plane of 0.0569 Å. The dihedral angle between the two nitro groups is 90.00 (5)°. In the crystal, the ions are linked by N-H⋯Cl interactions, forming a chain along the c-axis direction, and C-H⋯O inter-actions, forming a layer parallel to (010).