The title compound, 3C6H4N4O2S2.2C3H7NO.4H2O, comprises three 2,2'-disulfanylidene-5,5'-biimidazoli dinylidene-4,4'-dione molecules, two dimethylformamide molecules and four water molecules arranged around a crystallographic inversion centre. The non-H atoms within the 5,5'-biimidazolidinylidene molecule are coplanar and these molecules aggregate through N-H...S hydrogen-bonding interactions with cyclic motifs graph set R22(8), giving two-dimensional ribbon structures which are close to being parallel. The two independent water molecules associate to form centrosymmetric cyclic hydrogen-bonded (H2O)4 tetrameric units graph set R44(8). The ribbon structures extend along the a axis and are linked through the water tetramers and the dimethylformamide molecules by a combination of two- and three-centre hydrogen bonds, giving an overall three-dimensional structure.