In a series of 79 elective and ruptured abdominal aortic aneurysm resections, the autotransfuser manufactured by the Bentley Laboratories was used in 50 patients. These 50 patients, in whom the average amount of autotransfused blood was 1,500 cc, required a smaller number of intra- and postoperative transfusions, maintained satisfactory recovery hematocrit levels and had an essentially unchanged platelet count throughout the first 24 hours. There was no evidence of laboratory or clinical coagulopathy. The autotransfusion equipment was set up and operated by the patients' technician, and proved devoid of air embolism or clotting components. Although there are many patients whose aneurysms are easily removed and grafted and who require a small number of whole blood transfusions, there still remain operative traps and pitfalls in many patients that suggest to us that the autotransfuser is a security system, and thus it is routinely set up in all cases.