The vertical iron-cyclopentadienyl distance in ferrocene has been determined using ab initio coupled-cluster theory. At the CCSD level, a TZV2P basis set yields a metal-ligand distance of 1.664 Angstrom with all 96 electrons correlated and 1.672 Angstrom with 66 electrons correlated. With 66 electrons correlated at the CCSD(T) level the equilibrium distance is 1.660 Angstrom, in agreement with experiment (1.66 Angstrom).