Fibreoptic endoscopes have been responsible for outbreaks of infection with bacteria although viral transmission has been reported only once. The emergence of human immunodeficiency virus (HIV) has prompted a review of infection control practices in endoscopy units because of the theoretical possibility that HIV might be transmitted at endoscopy. Recent studies have shown that bronchoscopes and gastroscopes used on AIDS patients become contaminated with HIV genetic material although cleaning equipment in detergent removes all traces of the virus. Thorough precleaning has been shown to eliminate even high titres of HIV from endoscopes and 2% alkaline glutaraldehyde has been found to inactivate the virus rapidly even if the virus is dried in serum to a surface. These findings support the British Society of Gastroenterology recommendations for the cleaning and disinfection of endoscopic equipment and demonstrate that a uniform policy of infection control is practicable in endoscopy units.