The cancer pattern among Inuit in the Circumpolar area is remarkably different from those of other populations in the world. The current paper summarizes the most important risk factors in Canadian Inuit residing in the Northwest Territories, northern Quebec (Nunavik) and Labrador, particularly during the time period 1969-1988 covered by the study. Factors considered include: the geographic area and physical environment; population and human environment, including fertility and life expectancy; lifestyle and diet, including tobacco and alcohol use; other lifestyle factors, and health conditions; and health services and cultural accessibility. Development of the cancer registry and population databases supporting the analysis of cancer rates is described. The information in the present paper is needed to interpret cancer incidence patterns and differences among the Circumpolar Inuit of Canada, Alaska and Greenland.