In the title compound, [Mn(C(2)N(3))(NO(3))(C(24)H(16)N(6))(H(2)O)], the central manganese(II) ion is hepta-coordinated to a tridentate 2,3,5,6-tetra-2-pyridylpyrazine ligand (tppz), a bidentate nitrate ligand, a terminal monodentate dicyanamide ligand (dca) and a water mol-ecule. The structure contains isolated neutral complexes, which are linked by O(water)-H⋯N hydrogen bonds generating chains along [010].