In the cation of the title compound, [Mn(C(18)H(18)N(2)O(4))(H(2)O)(2)]ClO(4)·0.5C(12)H(24)O(6)·H(2)O, the Mn(III) ion is coordinated by two water O atoms, and two O atoms and two N atoms from the tetradentate 6,6'-dimeth-oxy-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]di-phenolate ligand, completing a distorted octa-hedral geometry. One O atom of the 18-crown-6-ether is disordered over two positions with occupancies of 0.70 (2) and 0.30 (2).