The use of medical screening and biological monitoring has seen substantial changes in the past two decades specifically in the provision of occupational medical services. For example, national surveys of workplaces conducted by the National Institute for Occupational Safety and Health (NIOSH) showed that the provision of off-site medical care to workers increased from 19.6% in 1972-1974 to 57.8% in 1981-1983, although the percent of workers receiving on-site services remained stable during the same period. After a recent survey in 1990-1991, the Occupational Safety and Health Administration (OSHA) estimated that 6.3% of US industries have a medical surveillance program at their individual establishment. We reviewed NIOSH documents, OSHA's Code of Federal Regulations, and texts on biological monitoring and medical screening for recommendations on medical surveillance of workers. This report summarizes the medical tests (including biologic monitoring) recommended or used by independent investigators and by the government for OSHA-regulated substances to provide guidance to physicians and occupational health professionals in accessing the pertinent literature; the utility of the recommendations is not evaluated.