Between January 1986 and December 1986, 106 Sorin-Pericarbon (new prostheses made of bobine pericardium) valves were implanted by our group: the object of this paper is to report the medium-term results of this new bioprosthesis. The probability of degeneration-free function at 4 years was 96.5 +/- 3.7% in patients with aortic valve replacement; the probability of reoperation-free survival for all patients was 95.2 +/- 3.3% and 96.5 +/- 3.7% for patients with aortic valve replacement with this prosthesis. The results of this new Sorin-Pericarbon bioprosthesis at medium-term are satisfactory and need to be confirmed at long-term by further follow-up.