4-[(2-Chloro-ethyl)amino]quinolinium chloride monohydrate.

In the title salt hydrate, C(11)H(12)ClN(2) (+)·Cl(-)·H(2)O, the quinolin-ium core is essentially planar (r.m.s. deviation = 0.027 Å) with the chloro-ethyl side chain being almost orthogonal to the core [C-N-C-C torsion angle = -80.0 (3)°]. In the crystal packing, the water mol-ecule bridges three species, forming donor inter-actions to two chloride anions and accepting a hydrogen bond from the quinolinium H atom. The chloride anion accepts a hydrogen bond from the amine N atom with the result that a two-dimensional supra-molecular array is formed in the ac plane. A C-H⋯Cl interaction also occurs.