The title complex, K₂[Ni₂(C₆H₅O₇)₂(H₂O)₄]·4H₂O, is a dinuclear centrosymmetric anionic octa­hedral complex, involv­ing citrates as tridentate and bridging ligands, and coordinating water mol­ecules. An extensive network of hydrogen bonds connects the complex anions through the two unique uncoordinating water mol­ecules. The K⁺ counter cation is surrounded by seven O atoms in the form of an irregular polyhedron and further stabilizes the crystal packing.