According to the theory of hormesis small amounts of some agents have a quali- tatively different (usually opposite) effect than large amounts. Advocates of radiation hormesis try to prove based on epidemiological and other evidence that small amounts of ionizing radiation are beneficial to human health and reduce in particular the probability of development of malignant tumours. The present state of knowledge however does not make it possible to adopt in the system of radiation protection the idea of hormesis instead of the linear non-threshold theory of action of ionizing radiation. Despite this it is important to study problems of radiation hormesis because if this theory proves correct it could save enormous amounts of money spent at present on protection from ionizing radiation.

        Key words: hormesis - ionizing radiation