In the title compound, C(9)HI(3)O(6)·2H(2)O, the mol-ecule is located on a twofold axis that gives rise to disorder of the carboxyl group. This disorder is correlated with the disorder of one of the H atoms of the water mol-ecule. The carboxyl group is twisted relative to the attached benzene ring by 75.1 (4)°. The intra-molecular I⋯O distance is 2.112 (6) Å. Mol-ecules are linked via O-H⋯O hydrogen bonding, C-I⋯O halogen bonding, with I⋯O distances in the range 3.156 (5)-3.274 (6) Å, and dipolar C=O⋯C=O inter-actions between the carboxyl and carboxyl-ate groups, with an O⋯C distance of 2.944 (10) Å.