The crystal structure of the title compound, [Cu(2)(C(2)H(4)O(6)PS)(OH)(H(2)O)(2)]·3H(2)O, consists of two Cu(2+) ions, one (O(3)PC(2)H(4)SO(3))(3-) ion and one OH(-) ion, as well as five water mol-ecules, two of which are coordinated to Cu(2+). The Cu(2+) ions are coordinated by six O atoms. The CuO(6) polyhedra are connected by μ- and μ(3)-O atoms into zigzag chains along the b axis. These chains are further connected by -CH(2)CH(2)- groups to form layers, in turn building a three-dimensional framework via hydrogen bonding.