In the title compound (systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 2-chloroacetate), C4H8N3O+·C2H2ClO2
−, the molecular aggregations are stabilized through classical (N—H⋯O) and non-classical (C—H⋯O and C—H⋯N) hydrogen-bonding interactions. The cations are linked to the anions, forming ion pairs through two N—H⋯O bonds that produce characteristic R
2
2(8) ring motifs. These cation–anion pairs are connected through another N—H⋯O hydrogen bond, leading to an R
4
2(8) ring motif. Further weak C—H⋯N interactions link the molecules along the a axis, while other C—H⋯O interactions generate zigzag chains extending along b
