In the title compound, [Mn(C(7)H(3)NO(4))(C(3)H(4)N(2))(C(12)H(8)N(2))(H(2)O)], the Mn(II) centre is surrounded by one bidentate phenanthroline ligand [Mn-N = 2.383 (3) and 2.421 (3) A], one tridentate dipicolinate ligand [Mn-N = 2.300 (3) A, and Mn-O = 2.300 (2) and 2.357 (2) A], one monodentate imidazole ligand [Mn-N = 2.238 (3) A] and one water molecule [Mn-O = 2.157 (3) A]. It displays a distorted pentagonal-bipyramidal geometry, with neighbouring angles within the equatorial plane ranging from 68.05 (9) to 77.48 (10) degrees . Intermolecular O-H...O hydrogen bonds link the molecules into infinite chains. The chains are crosslinked by hydrogen bonds involving the carboxyl O atoms of the dipicolinate ligand and the protonated imidazole N atom, leading to an infinite two-dimensional network sheet packing mode. The complete solid-state structure can be described as a three-dimensional supramolecular framework, stabilized by these intermolecular hydrogen-bonding interactions and pi-pi stacking interactions involving the phenanthroline rings.