In a retrospective, non-randomized study, the clinical and hemodynamic properties of 50 consecutively implanted hand-sewn allografts (group I), 50 stentless bioprostheses (group II) and 50 stented bioprostheses (group III) were compared. Preoperative hemodynamic and clinical data were identical in the three groups, except for age (group I: 54.4 +/- 8.7, group II: 67.0 +/- 5.1, group III: 70.0 +/- 5.1). Peak and mean gradients and flow characteristics with echo Doppler were performed at 1 week, 6 and 12 months. For the 21, 23 and 25 diameter prostheses, group differences between groups II and III in peak and mean gradients were not significant after 1 week and 1 year. In all groups, allografts had significantly lower gradients. Regurgitation (I-II) was present after 1 week and 1 year in group I: in 17/48 and 22/42 patients respectively, in group II 7/49 and 11/44 patients and in group III: in 1/49 and 2/44 patients. Early mortality and morbidity were comparable in all groups. Allografts have superior hemodynamic properties. Differences in gradients in groups II and III were not significant, though differences in technique allowed the implantation of a larger bioprostheses in group II. Regurgitation was most prominent in the allograft group. Immediate postoperative results were not influenced by the type of prosthesis.