The reaction of cobalt(II) nitrate with 5-amino-2,4,6-tri-iodo-isophthalic acid (ATPA) in pyridine solution leads to the formation of the title compound, {[Co(C(8)H(2)I(3)NO(4))(C(5)H(5)N)(3)(H(2)O)]·C(5)H(5)N}(n). The Co(2+) ion is six-coordinated by three N atoms, one water O atom and two O atoms from two ATPA ligands to form a distorted octa-hedral geometry. The two carboxyl-ate groups of ATPA act as bridging ligands connecting the Co(II) metal centers to form one-dimensional zigzag chains along the c axis, with Co-O distances in the range 2.104 (4)-2.135 (4) Å. The average Co-N distance is 2.171 Å. A classical O-H⋯N hydrogen bond is formed by the coordinating water mol-ecule and the pyridine solvent mol-ecule. The structure was refined from a racemically twinned crystal with a twin ratio of approximately 8:1.