From 1976 to 1984, 23 operations were performed on 22 patients with hemophilia (18 patients with factor VIII and four with factor IX deficiency). Elective procedures included resection of abdominal aortic aneurysm, liver transplantation, vagotomy/pyloroplasty, insertion of Mousseau-Barbin tube, colectomy, cholecystectomy, inguinal herniorrhaphy (four patients), colonoscopy/polypectomy, mediastinoscopy, arteriovenous fistula for dialysis, anal fistulectomy, and miscellaneous skin and soft-tissue procedures (five patients). Emergency operations were appendectomy (two patients), repair of bleeding liver biopsy site, and repair of an incarcerated inguinal hernia. There were two deaths (9%) within 30 days of operation, neither directly caused by the coagulopathy. Four patients had bleeding after surgery, which was treated with additional cryoprecipitate or factor concentrate. There were no nonhemorrhagic complications. Before operation, appropriate replacement therapy with factor VIII concentrate, cryoprecipitate, or fresh-frozen plasma was provided. Coagulation factor levels were measured before operation and monitored daily after operation. Generally, factor levels were raised to at least 1.0 U/ml and maintained at greater than 0.5 U/ml for 7 to 14 days after operation. However, when patients were treated with fresh-frozen plasma, plasma exchange was performed and factor levels of approximately 0.35 U/ml were achieved before surgery. We conclude that operations in patients with hemophilia can be accomplished safely with careful monitoring of coagulation factor levels and appropriate replacement therapy.