Heterozygous classical beta-thalassemia was found in 13 subjects of pure German descent, 11 of them from the Bergische Land (NW Germany) during the past three years. Clinically it became manifest in a moderate degree of anemia with marked hypochromia and reduced mean corpuscular volume. The number of red blood corpuscles and the value for serum iron were ascertained to be in the upper limits of normal or raised. The diagnosis of Mediterranean anemia was confirmed by hemoglobin electrophoresis with a rise in HbA2 of more than 3%. A slight increase in HbF may also occur. The importance of genetic counseling of thalassemia patients is emphasized. The occurrence of thalassemia even in pure German populations must be increasingly reckoned with.