Medically unexplained somatic symptoms are problematic in psychiatry, primary care settings, and other clinical areas. The burden they impose on health-care systems constitutes a significant public health problem. At the international symposium "Rethinking Somatoform Disorders," this problem was addressed by specialists working in somatoform disorders, psychiatric nosology, epidemiology, and biological and cross-cultural psychiatry. The meeting was the third of the Keio University International Symposia for Life Sciences and Medicine, in collaboration with the World Health Organization and the World Psychiatric Association.