We have made a simple 15-year retrospective epidemiological study of a part of South Moravia, district Břeclav, on the basis of genetic documentation of 245 congenital defects and 28 spontaneous abortions. The whole area was worked up by computer - geographical methods, and the occurrence of congenital defects was compared both in areas of severe chronic air pollution and in less contamined areas. There were three municipal areas, Mikulov, Břeclav-Poštorná, Velké Bílovice and their surroudings, in which an increased number of congenital de- fects was recorded. In the municipal area of Břeclav-Poštorná there was also a greater occurrence of organic sol- vents and phosphoric acid and a significantly higher occurrence of spontaneous abortions and at the same time a higher occurrence of heart defects.

        Key words: environment pollution, congenital defects