The use of the Continuous AutoTransfusion System (C.A.T.S; Fresenius Hemotechnology, Bad Homburg v.d.H., Germany), which conserves allogenic blood, is reported in 187 patients having abdominal aortic aneurysm repair during a 9-year period. patients were allocated to C.A.T.S if a Haemovigilance technician was available. A mean of 685 mL of retrieved blood was reinfused in 101 patients receiving C.A.T.S 61% required 2 U or less. All control patients required 3 U or more of allogenic blood. Allogenic transfusion in C.A.T.S patients decreased significantly (P <.0001). Mean intensive care unit stay was significantly reduced in C.A.T.S patients (P =.042). Mean postoperative hospital stay was 18 days for C.A.T.S group and 25 days in control patients (P =.014). The respective 30-day mortality was 12% versus 19% (P =.199). The C.A.T.S markedly reduced the amount of blood transfused, was associated with reduced intensive care unit and postoperative hospital stay, and was cost-effective.