Decontamination effectiveness of ammonium-ferric(lll)-hexacyanoferrate(II) (AFCF) in reducing the radiocaesium transfer into dairy goat milk was examined. The most effective reduction of radioactivity burden in milk was found in animals treated with AFCF as early as the first day of radionuclide contamination. Milk radioactivity concentrations in goats treated simultaneously with ¹³⁷CsCI and hexacyanoferrate were over 10-fold lower than those in the controls at all measurement time points. Decontamination efficiency was reduced when AFCF treatment was delayed.