Residual antigenicity of xenograft tissue after glutaraldehyde tanning may be a factor that determines calcification and durability of bioprostheses. We have pursued the concept of a nonantigenic, noncalcifying, more durable bioprosthesis. We previously described a technique for rapid intraoperative fabrication of an autogenous tissue heart valve (ATHV). That technique has been modified to improve reliability and ease of learning. With the modified technique, a geometrically perfect trileaflet valve can be made in 5 minutes. Although any suitable tissue can be used, the pericardial ATHV is the subject of this report. Autogenous pericardium immersed for 5 minutes in glutaraldehyde has proven satisfactory for valve construction. In vitro testing in the pulse duplicator and accelerated life tester has shown that the stent assembly is capable of function beyond 800,000,000 cycles without failure. In vivo testing has been performed in the juvenile sheep model as described by the National Institutes of Health group. Five sheep were maintained for 5 months postimplant before sacrifice. Explanted valves showed no tissue thickening or shrinkage, problems seen with earlier valves made with untreated autogenous tissue, and the leaflets remained pliable, free of the degenerative changes usually seen in the sheep model.