The title compound, C14H10Cl2N2O·H2O, has a nearly planar extended conformation [C-N-N-C = -173.66 (15)°]. The dihedral angle between the aromatic rings is 4.6 (2)°. The water mol-ecules alternate with benzohydrazide mol-ecules in chains formed by O-H⋯O hydrogen bonds which run parallel to the a axis. These chains are linked to neighboring chains through N-H⋯O and C-H⋯O inter-actions, forming a layer parallel to (001).