Fe-57 Mossbauer spectra of bis(isocyclopentadienyl)iron and its cationic form have been determined over the temperature range 90 less than or equal to T less than or equal to 300 K, and the hyperfine interaction and lattice dynamical parameters extracted from these data are compared to a number of structurally related oganometallics. The metal d-orbital involvement in the bonding to the cyclic ligands is discussed in detail.