The National Toxicology Program of the National Institute of Environmental Health Sciences within the National Institutes of Health is convening a workshop on March 10-11, 2016, to better understand the health effects of circadian disruption related to artificial light at night and shift work. The workshop will be held at the NIEHS office in Research Triangle Park, N.C. Attendance is limited to the first 100 registrants; however, additional webcast registration is available.