In the title complex, [Fe(NCS)2(C(4)H(2)N(6))2(H2O)(2)]n, the Fe(II) atom is on an inversion centre and the 4,4'-bi-1,2,4-triazole (btr) group is bisected by a twofold axis through the central N-N bond. The coordination geometry of the Fe(II) atom is elongated distorted FeN(4)O(2) octahedral, where the cation is coordinated by two N atoms from the triazole rings of two btr groups, two N atoms from NCS- ligands and two water molecules. Btr is a bidentate ligand, coordinating one Fe(II) atom through a peripheral N atom of each triazole ring, leading to a one-dimensional polymeric (chain) structure extending along [101]. The chains are further connected through a network of O-H...N and C-H...S hydrogen bonds.