Background: London accounts for nearly half of the national burden of tuberculosis. The incidence of tuberculosis has more than doubled in London in the past 15 years. Methods: Data from the enhanced tuberculosis surveillance 1999-2003, the national tuberculosis surveys of 1993 and 1998, and tuberculosis notifications were compared and analysed. Results: In 2003, 3048 patients with tuberculosis were reported in London, 45% of the national total. This represents an incidence of 41.3/100 000, five times higher than the rest of England and Wales, and in parts of London the incidence of tuberculosis is nine times the national average. 75% of people with tuberculosis in London are born abroad; nearly half have lived in the UK for <5 years, but a third for >10 years. 86% are from an ethnic minority group, and the incidence is highest in black Africans at 283/100 000 compared with 141, 141 and 8/100 000 for Pakistanis, Indians and whites, respectively. In absolute terms, a third of patients with tuberculosis in London are from Africa and nearly a third from the Indian subcontinent. Specific groups affected also include the homeless, prisoners, and hard drug and alcohol users as well as the immunosuppressed. Conclusions: London reflects the worldwide rise in tuberculosis, with increasing incidence in ethnic minorities. Work has been carried out to combat this rise, but more is needed. Tuberculosis control and prevention strategies should be mindful of the changing epidemiology of tuberculosis in London, and provide information, diagnosis and treatment tailored to the specific needs of the capital and its at-risk groups.