4-[(E)-2-(2-Chloro-benzyl-idene)hydrazin-1-yl]quinolin-1-ium chloride dihydrate.

In the title hydrated salt, C(16)H(13)ClN(3) (+)·Cl(-)·2H(2)O, a small twist is evident in the cation so that the chloro-benzene ring is not coplanar with the central hydrazinyl group [the N-C-C-C torsion angle = -4.8 (12)°]. The conformation about the imine N=C bond [1.284 (10) Å] is E. The components of the structure are connected into a three-dimensional architecture via O-H⋯O, O-H⋯Cl and N-H⋯Cl hydrogen bonds. One water H atom is disposed over two sites of equal occupancy.