Two cyano- and phenoxo-bridged hexanuclear (Ni2Dy2Fe2III)-Dy-II-Fe-III (1) and octanuclear (Ni4Dy2Fe2III)-Dy-II-Fe-III (2) trimetallic cyclic complexes have been obtained. They are the first trimetallic metallocycles. Magnetic studies reveal that 1 and 2 exhibit single-molecule-magnet behavior with an energy barrier of 17.9 K for complex 1 in a 2000 Oe static field and 25.0 K for complex 2 in a zero static field.