Tuberculosis (TB) continues to be a leading infectious cause of death worldwide, and it remains a serious public health problem in developing countries. To determine the prevalence of tuberculosis infection among garment workers, the authors conducted a retrospective prevalence survey of employees working in garment factories in Qatar from January 2000 to June 2003. A mass screening of garment factory workers was carried out by chest X-ray and Mantoux skin test at the Rumailah Hospital, Hamad Medical Corporation. The authors considered those workers with a purified protein derivative (tuberculin) reaction of >= 15 mm to be infected with TB, or to have a latent TB infection. Workers with active TB diseases were confirmed by histopathological and mycobacteriological examinations. The authors studied a total of 2,774 garment factory workers, and they found 43% of them to be infected (reaction >= 15 mm). The mean age of the infected subjects was significantly higher than that of the noninfected subjects (p <.001); 53% of the infected subjects were between 30 and 40 years of age. Indians and Pakistanis made up the most frequent nationalities among the infected subjects (50.0%), followed by Nepalis (44.1%). The prevalence rate of tuberculosis infection in garment workers was high. Overcrowding in factories and residential facilities increases the risk of TB transmission.