An international conference in Luxembourg on Ambient and Biological Monitoring in the Workplace brought out the difference in meaning between medical “surveillance” and medical “monitoring.” These are reveiwed against the Health Standards of the Occupational Safety and Health Administration (OSHA). The standards may be specification standards, that is, the details of the medical examinations and laboratory tests are specified; or they may be performance standards, where surveillance is largely left to the physician's discretion. Bearing in mind the limited number of qualified physicians available, OSHA, and therefore the Office of Occupational Medicine, treads narrow line between specifics and performance to obtain a pragmatic approach that will meet the mandate of the Occupational Safety and Health Act and ensure a safe and healthful workplace for all American workers.