An epidemiological survey of several chronic diseases in the Upernavik district, Northwest Greenland, is reported. The study population (approx. 1800 inhabitants) is one of the remaining whaling and sealing populations in Greenland. It was observed over the 25-year period 1950-74 as to the incidence of the diseases, which was based on all cases diagnosed in hospital during this period. The disease pattern of the Greenlanders differs from that of West-European populations, having a higher frequency of apoplexy and epilepsy but a lower frequency or absence of acute myocardial infarction, diabetes mellitus, thyrotoxicosis, bronchial asthma, multiple sclerosis and psoriasis. The distribution of cancer types differs from that of the Danish population, but the total incidence of cancer is of the same magnitude. Further comparable studies should be performed in Greenlandic districts that are characterized by more profound changes in life style, in order to elucidate the effect of these changes on the disease pattern.