Heterobimetallic cores are important units within the active sites of metalloproteins but are often difficult to duplicate in synthetic systems. We have developed a synthetic approach for the preparation of a complex with a Mn(II)-(μ-OH)-Fe(III) core, in which the metal centers have different coordination environments. Structural and physical data support the assignment of this complex as a heterobimetallic system. A comparison with analogous homobimetallic complexes, Mn(II)-(μ-OH)-Mn(III) and Fe(II)-(μ-OH)-Fe(III) cores, further supports this assignment.