It is possible to change the ionization state of iron in ZnS by light excitation in the visible and uv and by changing sample temperature. This can be confirmed by ESR-measurements. To clarify the nature of a new emission band (λmax = 980 nm) in ZnS: Fe a comparison between luminescence- and ESR-measurements has been performed. These results can be interpreted by assuming Fe3+ -ions as the emitting centers for the 980 nm luminescence. Furthermore a sensitization of this emission by the self-activated luminescence is concluded. © 1979.