The object of the study is the evaluation of a more than 8-year period of compulsory vaccination against measles in the CSR. So far, a total of 1,850,000 children have been vaccinated. A pronounced decrease has been achieved in morbidity while mortality and lethality reached zero values as early as in 1973. Changes occur in the epidemiological characteristic of measles manifested primarily by the shift of the age distribution of notified cases into older age groups, by continuous prolongation of interepidemic intervals and by gradual disappearances of typical seasonal incidence. Regular immunological surveys have become the most efficient tools in epidemiological surveillance of this infection and in monitoring the vaccination programme. The results of immunological surveys indeed led to the introduction in 1975 of so-called second vaccination compulsory for children starting the first year of school attendance. Up to the present, a total of 24,000 cases of measles have been recorded in children vaccinated earlier, i.e., 1.5% of the total of vaccinated children. It can be expected that measles as a mass disease will be eliminated from the territory of the CSR in the next few years.