Three different cereal cultivated fields (rice, maize/wheat, wheat/barley) were selected and soil samples were collected in order to study the behaviour of the radiocesium deposited over the crops after the Chernobyl accident fall-out (April 1986) together with its distribution at different ground depths. For each field, soil samples were removed during the sowing (Oct–Nov '86), in Spring (Apr '87) and during the harvest time (Jun–Sept '87). The40K concentration and stable potassium content in soil was also evaluated by nuclear spectrometry and by atomic absorption spectrometry. Beside soil sample measurements, the cultivated cereals produced in the 1986 harvest (rice, maize, wheat) were analyzed to evaluate the deposited contamination, and in order to evaluate the contamination during the growth and naturation we also analyzed whole plants (roots, stalks, grains) of the cultivated cereals (rice, wheat, barley) in 1987. Results are presented and discussed.