The title compound, [Dy(2)(C(2)H(3)O(2))(6)(H(2)O)(4)].4H(2)O, crystallizes in the form of dimeric units related by an inversion centre. Each cation is nine-coordinate, binding to two water molecules and three acetate groups, two of which are bidentate and the third tridentate. This last acetate group acts as a bridge between neighbouring metal atoms, leading to an intradimer Dy...Dy separation of 4.170 (1) A.