Bulk stable (α-FeSi 2 , β-FeSi 2 ) and epitaxially stabilized (γ-FeSi 2 , Fe 0 . 5 Si which has the CsCl structure and 50% Fe vacancies) phases with the stoichiometry Fe:Si = 1:2 grown on Si(111) by molecular beam epitaxy have been studied by e 5 7 Fe conversion electron Mossbauer spectroscopy. The Mossbauer parameters are discussed with respect to the local surrounding of the Fe atoms. From the angular dependence of the line intensities in the case of β-FeSi 2 the hitherto accepted interpretation of the spectra in terms of quadrupole coupling of the lines is discarded. Information about the defect (Fe vacancies) distributions in Fe 0 . 5 Si and α-FeSi 2 obtained from the population fractions of the different sites are reported. The possible nature of the observed spectrum for the γ-FeSi 2 phase is also discussed.