In Cambodia the prevalence of both tuberculosis (TB) and Human Immunodeficiency Virus (HIV) infection is high. Data suggest that aggressive management of HIV infection, which includes Anti-Retroviral Therapy (HAART) during treatment of TB, decreases both morbidity and mortality. On the other hand, the use of HAART for patients with TB may cause severe complications due to drug-drug interactions, and occasionally a temporary exacerbation of symptoms. These reactions may be particularly severe when HAART is started soon after the start of TB treatment.