In the title compound, [Ni(C(12)H(11)N(4)S(2))(C(12)H(12)N(4)S(2))]Cl·H(2)O, the Ni(II) ion is chelated by two 2-acetyl-thia-zole-3-phenyl-thio-semicarbazone ligands, forming a distorted octa-hedral complex. The metal ion is coordinated via the thia-zole nitro-gen, imine nitro-gen and thione sulfur atoms from each thio-semicarbazone ligand, and two coordinating units lie almost perpendicular to each other give dihedral angle = 81.89 (1)°]. One thio-semicarbazone unit is found to bind a chloride anion through two hydrogen bonds, while the other is linked with the disordered crystal water molecule. Two mol-ecules are connected to each other through an inter-molecular N-H⋯S inter-action, forming a centrosymmetric dimer. Dimers are linked into sheets by π-π stacking of two phenyl rings [shortest C⋯C distance = 4.041 (3) Å].