In the title compound, [Ni(C(4)H(4)O(4)S)(C(6)H(6)N(4)S(2))(H(2)O)]·H(2)O, the Ni(II) cation assumes a distorted octa-hedral coordination geometry formed by a diamino-bithia-zole (DABT) ligand, a thio-diacetate (TDA) dianion and a coordinated water mol-ecule. The tridentate TDA chelates to the Ni cation in a facial configuration, and both chelating rings display the envelope conformations. The two thia-zole rings of the DABT ligand are twisted with respect to each other, making a dihedral angle of 9.96 (9)°. Extensive O-H⋯O, N-H⋯O and weak C-H⋯O hydrogen bonding is present in the crystal structure.