In the title heteronuclear complex, [CuSm(C(19)H(20)N(2)O(4))(NO(3))(3)(CH(3)COCH(3))], the Cu(II) ion is five-coordinated by two O and two N atoms from the 6,6'-dimeth-oxy-2,2'-[propane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolate ligand (L) and by an O atom from the acetone mol-ecule in a square-pyramidal geometry. The Sm(III) ion is ten-coordinated by six O atoms from the three nitrate ligands and four O atoms from the L ligand. In L, the C atoms of the diamino-propane fragment are disordered over two positions in a 0.674 (10):0.326 (10) ratio.