4-Amino-2-chloro-benzoic acid.

The title compound, C(7)H(6)ClNO(2), crystallizes with two roughly planar mol-ecules in the asymmetric unit (r.m.s. deviations = 0.073 and 0.074 Å). The amine H atoms of the two mol-ecules have opposite orientations. In the crystal, mol-ecules are linked into dimers by pairs of O-H⋯O hydrogen bonds, generating R(2) (2)(8) loops. N-H⋯N and N-H⋯Cl hydrogen bonds link the dimers into a three-dimensional network. The crystal studied was found to be a racemic twin.