Claims that fluoridation of the municipal water supply causes cancer in humans have not been substantiated by independent objective studies in the United States of America, Canada, or New Zealand. After thorough reexamination of the earlier publications from other countries, and our own study of data available for the New Zealand population, we consider the 1976 statement of the Royal College of Physicians seems more than ever justified: "There is no evidence that fluoride increases the incidence or mortality of cancer in any organ".