After a historical introduction the authors analyze contemporary views on the aetiology, pathogenesis and genetics, they characterize the clinical picture and histopathological findings in Alport's syndrome. They emphasize that Alport's syndrome is more frequent than generally reported and that it deserves therefore appropriate attention in the differential diagnosis of renal diseases. They draw attention to the results of most recent genetic research which makes it possible to detect gene carriers of Alport's syndrome as well as early prenatal and postnatal diagnosis of this most frequently progressing hereditary nephritis.