A retrospective epidemiological analysis was performed of Mycobacterium tuberculosis infections in the Al Ain Medical District, Al Ain, United Arab Emirates (U.A.E.) during the period 1995-2000. The mean incidence for the study period was 7.1%, more than 3 times that reported for the period 1983-1992 (2.1%). For the years 1997 through 2000, the highest incidences (approximately 5-7% of tested) were from health care facilities that cater exclusively for citizens and long-term residents of the U.A.E. Corresponding rates for the immigrant visa applicants (non-citizens) were lower and showed a dramatic decrease from approximately 18% in 1995 to approximately 2% in 2000. Most importantly, the number of multidrug-resistant cases showed an increase from 1.4% during the period August 1997-December 1998 to 8.5% during the period January 1999-July 2000. Analysis of 7 different isolates by restriction fragment length polymorphism (RFLP) showed RFLP patterns that did not match > 4000 individual patterns from 32 countries, suggesting the possible presence of M. tuberculosis strains unique to the U.A.E. Our data demonstrate local transmission of M. tuberculosis in the Al Ain Medical Region of the U.A.E.