PURPOSE OF REVIEW: Multiple drug-resistant tuberculosis is increasing globally, particularly in Eastern Europe. This review summarizes advances in our understanding of the epidemiology, diagnosis, and treatment of MDRTB in 2002-2003. RECENT FINDINGS: The annual incidence of multiple drug-resistant tuberculosis globally is unknown because systematic drug resistance data have been produced from only 60 countries internationally. Nevertheless, countries with effective tuberculosis programs see approximately 1% multiple drug-resistant tuberculosis among new cases annually. Hot spots with high rates such as countries of the former Soviet Union exist, and modeling of existing data suggests that between 250,000 and 500,000 new MDRTB cases occur globally. Unfortunately, mortality from multiple drug-resistant tuberculosis, particularly with HIV co-infection, remains high, and the global economic costs are also substantial. Research has produced many rapid and novel diagnostic methods for multiple drug-resistant tuberculosis, but culture-based methods remain the mainstay of analyzing resistance to drugs other than isoniazid and rifampicin. Treatment of multiple drug-resistant tuberculosis is prolonged, and survival requires therapy with at least three agents to which the bacteria are susceptible. Individualized therapy forms the gold standard of treatment, but the high laboratory costs associated with this approach have led to studies of standardized treatment in middle-/low-income countries. Studies in Peru examined both approaches with comparable success. Nevertheless, even standardized treatment requires an accurate survey of drug resistance and an understanding and correction of the causes of the high rates of multiple drug-resistant tuberculosis. SUMMARY: The global rates of multiple drug-resistant tuberculosis are unknown. Rapid and early diagnosis of multiple drug-resistant tuberculosis improves survival and is of a public health benefit. Treatment requires prolonged effective combination chemotherapy.