HIV (human immunodeficiency virus) infection is prevalent in many areas of sub-Saharan Africa. Seropositivity rates reach 10-15% in urban adults, 21% in critically ill adults and 30% in surgical inpatients aged 21-40 years. AIDS (acquired immune deficiency syndrome) is a multisystem disease which presents to the surgeon with a wide range of pathologies including Kaposi's sarcoma, lymphadenopathy and sepsis. The more common sites for sepsis are the female genital tract, anorectum, pleural cavity, soft tissues (necrotizing fasciitis) and bone and joints. To prevent iatrogenic HIV infection more use should be made of autologous blood. Occupational exposure to HIV infection can be minimized by double-gloving, protecting the eyes when operating and ensuring that theatre gowns are waterproof. The risk of HIV infection from a needlestick injury is 0.4%. Although contact with blood during a surgical procedure is common, the risk is lower than for a hollow needlestick injury.