During August 17th-21st, 2014, the University of Alaska Anchorage, along with other local, state, and federal agencies throughout Alaska, will host the 20(th) International Epidemiological Association's (IEA) World Congress of Epidemiology (WCE 2014). The theme for this Congress is "Global Epidemiology in a Changing Environment: The Circumpolar Perspective." The changing environment includes the full range of environments that shape population health and health inequities from the physical to the social and economic. Our circumpolar perspective on these environments includes views on how political systems, work, immigration, Indigenous status, and gender relations and sexuality affect the global world and the health of its people. Suggestions and insights from the 3(rd) North American Congress of Epidemiology (2011) and the first-ever joint regional workshop co-organized by the IEA North American Region and the IEA Latin American and Caribbean Region held at the 19(th) IEA World Congress of Epidemiology (2011) have helped direct the focus for WCE 2014. Since the Arctic regions are feeling the effects of climate change first, we believe focusing on the emerging data on the health impacts of climate change throughout the world will be an important topic for this Congress. This will include a broad range of more traditional epidemiology areas such as infectious disease epidemiology, environmental epidemiology, health disparities, and surveillance and emergency preparedness. Addressing health inequities and promoting health equity is likewise a key concern of the Congress. This Congress will also host presentations on injury epidemiology, occupational health, infectious diseases, chronic diseases, maternal and child health, surveillance and field epidemiology, mental health, violence (from self-directed, e.g., suicide, to interpersonal to structural), psychoactive substance use (including tobacco), and measures of subjective health. Attention will be given to epidemiology's theoretical frameworks and emphasizing knowledge translation, from epidemiology to health systems, to policy, and to the broader public. We also plan to offer many hands-on workshops including practical uses of epidemiology to improve health systems and reduce health inequities within and between countries; the manner in which epidemiology can inform public health practice; the understanding and use of the Dictionary of Epidemiology; and many others.