The transmission and occurrence of Trichinella spp according to the zoogeography of different climatic conditions, socioeconomy and human activity are discussed. Comparing arctic, subarctic and temperate regions, it appears that the species of Trichinella present, the composition of the fauna and the human activity are all very important interacting factors affecting epidemiology. In Greenland, where only sylvatic trichinellosis is present, the high prevalence in wildlife appears closely connected with polar bear hunting. In the Scandinavian countries, the prevalence of both sylvatic and domestic trichinellosis differ widely. Denmark is regarded as Trichinella-free, in the case of domestic trichinellosis and sylvatic trichinellosis is very rare. In Sweden and Norway. Trichinella is found in wildlife but domestic trichrnellosis is rare. In Finland, both domestic and sylvatic trichinellosis have increased dramatically during the last decade. Among the Scandinavian countries, Finland also has the largest populations of carnivorous mammals. In the Baltic states, Trichinella is frequently found in wildlife and domestic trichinellosis is increasingly diagnosed. The high prevalence in the widespread wildlife populations may have epidemiological importance in relation to the recent changes in production and infrastructure in these former Soviet states.