The National Institute of Environmental Health Sciences (NIEHS), located in Research Triangle Park, North Carolina, is one of 27 research institutes and centers that comprise the National Institutes of Health (NIH), U.S. Department of Health and Human Services (DHHS). The mission of the NIEHS is to reduce the burden of human illness and disability by understanding how the environment influences the development and progression of human disease.

The NIEHS traces its roots to 1966, when the U.S. Surgeon General announced the establishment of the Division of Environmental Health Sciences within the NIH. In 1969, the division was elevated to full NIH institute status. Since then, the NIEHS has evolved to its present status as a world leader in environmental health sciences, with an impressive record of important scientific accomplishments and a proud history of institutional achievements and growth under the leadership of former directors Paul Kotin, M.D. (1969–1971), David P. Rall, M.D., Ph.D. (1971–1990), and Kenneth Olden, Ph.D. (1991–2005).

Today, under the guidance of its 2006–2011 Strategic Plan, the NIEHS is expanding and accelerating its contributions to scientific knowledge of human health and the environment, and to the health and well-being of people everywhere.