The number of new cases--or incidence--of tuberculosis is increasing in nearly every region of the world. A number of forces have resulted in the increased incidence of TB in developed countries, including the HIV epidemic, homelessness, and emigration from highly endemic regions. Although the number of new cases in Canada is relatively constant, the TB experience in the United States serves as a reminder that this situation could change rapidly. The appearance of multidrug-resistant tuberculosis has added to the urgency of situation. The basic methods of preventing TB transmission include preventing the release of the organism into the air, removing the organism from the air, and preventing the inhalation of the organism. Identifying and appropriately treating every person with active tuberculosis is an extremely important component of the control strategy; adequate ventilation, filtering air, and ultraviolet germicidal irradiation are methods used to remove the organism from the air; and masks and other personal protective devices, such as high-efficiency particulate air filters (HEPA), have been suggested as a means of preventing inhalation of the organism. In addition, identifying new TB infections and using chemoprophylaxis often prevents infection from progressing to active disease. Given the route by which tuberculosis is transmitted, it is necessary for both dentists and allied dental personnel to be aware of the risks they may face in day-to-day practice, and the means by which they can protect themselves and their patients.