The presentation, operative management and final diagnosis were reviewed in 28 patients with AIDS (27 men and one woman) who underwent emergency laparotomy. On clinical and radiological examination, six patients showed features of toxic megacolon, five patients had small bowel obstruction, six patients had localized peritonitis and three had perforated viscus with generalized peritonitis. The most common disease processes were acute colitis in seven patients (associated with cytomegalovirus (CMV) infection in six), intra-abdominal lymphoma in five patients, acute appendicitis in five patients (associated with CMV infection in two), and atypical mycobacterial (MAI) infection in four patients. Two perioperative deaths occurred; one in a patient with acute pancreatitis and a second with generalized peritonitis. Later deaths were due to progression of AIDS, and patient survival at 1 month, 3 months and 6 months was 89 per cent, 64 per cent and 48 per cent, respectively. Lower operative mortality than in previously reported series may be due to earlier intervention in CMV toxic megacolon. Surgery, however, conferred less benefit in patients with acute abdominal pain from MAI infection or lymphoma. With careful patient selection, emergency laparotomy may achieve worthwhile palliation in patients with AIDS.