In 1959 and 1960, during the annual survey conducted by the Federal Northern Health Services in the area of the Northwest Passage, the diet and living conditions of some 1500 Eskimos who live in this area were studied and blood and urine samples were obtained from 40-50% of this population. Hemoglobin, blood cell morphology, serum protein-bound iodine, serum proteins, serum lipids and serum total cholesterol estimations, urinalyses, and agglutination studies for brucellosis were carried out. Hemoglobin levels were in the normal range; however, increased contact with civilization appeared to be associated with lower hemoglobin levels. Eleven per cent of the Eskimos showed eosinophilia. Serum proteins were normal. Serum lipids and serum cholesterol levels were higher in Eskimo children living in a government residential school than in a comparable group living on the Barren Lands. Serum protein-bound iodine levels were in the upper euthyroid range. Diabetes mellitus occurs among Eskimos. Sporadic cases of brucellosis also occur.