The possible use of ammonium-ferrichexacyano-ferrate (AFCF) as a countermeasure for soil-plant transfer of radiocaesium is evaluated. On a sandy agricultural soil, AFCF application rates of 10 and 100 g AFCF m - 2 reduced radiocaesium transfer to ryegrass by a factor of 25 and 225, respectively, without affecting plant growth. Even additions of only 1 g AFCF m - 2 resulted in a 4-fold reduction of the radiocaesium transfer factor. Additions of less than 0.1 g AFCF m - 2 were not effective in reducing radiocaesium transfer to rye grass. Reductions in transfer with AFCF addition can be estimated and have been quantified using an appropriate regression equation.