Background: Tuberculosis once was thought to be nearly eradicated, but there was a 14% increase in cases of tuberculosis between 1985 and 1993, although decreases were observed in both 1994 and 1995. To reduce spread of this disease, health care workers must be familiar with tuberculosis, its signs, symptoms, and modes of transmission. In October 1994 the Centers for Disease Control and Prevention issued 'Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health Care Facilities.' The combination of persistently high tuberculosis case rates, the development of multidrug-resistant tuberculosis, the new Centers for Disease Control and Prevention recommendations, and Occupational Safety and Health Administration enforcement has mandated large-scale training in health care facilities. Methods: A tuberculosis control plan was developed and the train-the-trainer concept was selected after review of the hospitals tuberculosis risk assessment, staff members requiring training, and available teaching staff. The training program that was developed included tuberculosis pathology and transmission, national and local epidemiology, placement and evaluation of skin tests, and an algorithm to assist in determining when isolation is indicated. Results: One hundred forty-six trainers were trained in 4 days. During the next quarter, 66% (1989/3000) of staff members requiring instruction were trained. The total cost involved in development and training was approximately $26,000 and involved 1600 person-hours. Conclusion: Tuberculosis training should be directed toward high-risk areas, including intensive care units, emergency departments, and acute medicine wards. Large- scale training is time-consuming and expensive. Evaluation remains difficult. To facilitate compliance, pretest and posttest results should be provided, linked to Occupational Safety and Health Administration compliance and quality indicators for the hospital.