The title compound [systematic name: 5-chloro-2-(2,4-dichlorophenoxy)phenol], C12H7Cl3O2, is a biologically relevant molecule with biocide activity. It crystallizes in the chiral trigonal space group P3(1) with one molecule in the asymmetric unit. As in biological adducts, the two aromatic rings are almost mutually perpendicular, with this structural feature leading to a distribution of the pendant -OH groups to maximize the formation of O-H...O hydrogen bonds. This arrangement leads to a chain of molecules running parallel to the c axis and having a C(2) graph-set motif at its core.