HIV/AIDS continues to be a significant world health issue. Patterns of referral to intensive care units (ICU) have changed in parallel with advances in treatment. Proven Pneumocystis therapy and the introduction of antiretroviral drugs have increased life expectancy. Lower respiratory tract infection predominates as a reason for ICU admission. Pneumocystis jirovecii, TB, fungi and bacterial infections rank highly as respiratory pathogens and should be considered potentially causative. Neurological pathology and severe sepsis commonly necessitate ICU admission in this population. The timing of highly active antiretroviral therapy (HARRT) remains controversial in critically ill patients. Therapy may be difficult due to associated drug interactions, lack of intravenous drug formulation and known toxic side effects. Improvement in survival may have resulted as much from general improvements in ICU care as from advances in highly active antiretroviral therapy, notably lung protective ventilation strategies and approaches to the early recognition and management of sepsis. HIV infection is now considered a chronic illness and should not be seen as a bar to ICU admission. Many HIV-positive patients present with non-HIV related illness and can be expected to make as good a recovery as non-infected patients. © The Intensive Care Society 2010.