The NIOSH program for research and prevention of job related illness and injury is described. A brief history of occupational risks and the development of United States safety legislation are provided. Data gathering efforts, including industry wide studies, a national occupational hazard survey, and NIOSH research initiatives, are reviewed. Other NIOSH activities, including information dissemination; manpower training; and special projects concerned with occupational cancer, nonmalignant respiratory disease, women in the workplace, new energy technology, deep sea diving, control technology, and safety, are cited. Unresolved issues, such as the need to regulate occupational and environmental exposures on an industry wide basis and to study the long term implications of new industrial facilities, are discussed.