IN THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: 2,3-dichloro-benzene-1,4-diol 2,3-dichloro-cyclo-hexa-2,5-diene-1,4-dione monohydrate), C(6)H(4)Cl(2)O(2)·C(6)H(2)Cl(2)O(2)·H(2)O, the 2,3-dichloro-1,4-hydro-quinone donor (D) and the 2,3-dichloro-1,4-benzoquinone acceptor (A) mol-ecules form alternating stacks along [100]. Their mol-ecular planes [maximum deviations for non-H atoms: 0.0133 (14) (D) and 0.0763 (14) Å (A)] are inclined to one another by 1.45 (3)° and are thus almost parallel. There are π-π inter-actions involving the D and A mol-ecules, with centroid-centroid distances of 3.5043 (9) and 3.9548 (9) Å. Inter-molecular O-H⋯O hydrogen bonds involving the water mol-ecule and the hy-droxy and ketone groups lead to the formation of two-dimensional networks lying parallel to (001). These networks are linked by C-H⋯O inter-actions, forming a three-dimensional structure.