The purpose of this study was to analyze our experience with the CarboMedics bileaflet prosthetic heart valve. Between March 1991 and October 1998, 1,503 valves were implanted in 1,350 patients. Follow up was 99% complete and totaled 4,342 patient-years (pt-yr). Mean (± SEM) survival rates at one and five years were 92.0 ± 0.7% (n = 1,109) and 80.0 ± 1.3% (n = 335). Freedom from valve-related complications (linearized rate 5.6%/pt-yr) at one and five years was 89.5 ± 0.8% (n =1,031) and 76.3 ± 1.4% (n = 284). Linearized rates for bleeding events were 2.19%/pt-yr, thromboembolic events 2%/pt-yr, operated valvular endocarditis 0.18%/pt-yr, valve thrombosis 0.14%/pt-yr and non-structural dysfunction 1.22%/pt-yr. Freedom from reoperation at one and five years was 98.5 ± 0.3% (n = 1,107) and 97.3 ± 0.5% (n = 334). Mid-term results show that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.