In the structure of the title compound, [Ag(C(2)H(3)O(2))(C(12)H(6)N(2)O(2))]·3H(2)O, the Ag(I) atom is coordinated by both 1,10-phenanthroline-5,6-dione N atoms and one O atom from the acetate anion. The three water mol-ecules are involved in extensive hydrogen bonding to each other and to the acetate O and 1,10-phenanthroline-5,6-dione O atoms. In addition, there are weak C-H⋯O inter-actions.