In Czechoslovakia obligatory registration of all cases of cancer is introduced in 1953. In this paper are informed of the most important results of the analysis of indexes which were find out in the whole country, of the results of epidemic studies in Prag, and of the epidemic studies in the district of Kolín. From 1959 to 1975 the rate of bronchial carcinoma has increased in men from 47 to 86 of the male population, in women from 6 to 9 of the female population.