The occupational medicine residency program of NIOSH was discussed. The program, actively operated by NIOSH since 1981, was an accredited training program in occupational medicine that emphasizes the development of epidemiological skills in occupational physicians. Activities of residents in the program were described. Program residents were sent, frequently on short notice, to worksites anywhere in the United States to assess outbreaks of occupational illness or to evaluate the possible health consequences of occupational exposure. Typical investigations conducted by NIOSH residents in recent years have included evaluations of cases of sudden death in sewer workers which were linked to inhalation of hydrogen-sulfide (7783064), an apparent cluster of cases of detached retina in laser welders, the occurrence of neuropathy and encephalopathy in plastics workers, an epidemic of asthma in seafood processors, an outbreak of respiratory symptoms in office workers, and incidents of reproductive dysfunction in farm workers exposed to ethylene-dibromide (106934). The authors assert that the NIOSH occupational medicine residency program provides valuable experience with representative patient populations, a high level of training in pathology, and good academic research, and technical support.