The effects of prosthetic and homograft aortic valves on ventricular hemodynamics were examined. Resting and exercise hemodynamic evaluations were made echocardiographically in patients who received either homograft (n = 19) or prosthetic (n = 19) aortic valve replacements. Electrocardiographic and hematologic examinations were also performed. Left ventricular (LV) mass (LVM) and mass index (LVMI) were each reduced postoperatively in both groups, but this was significantly greater after homograft replacement. In the homograft group, reductions in interventricular septum (IVS) and posterior wall (PW) diameters were reduced significantly, and ejection fraction (EF) was significantly increased. The exercise pressure gradient of the homograft group was significantly less than in the prosthesis group. Both groups showed improvement in electrocardiographic evaluation of LV hypertrophy and there was a correlation between V₁ >24 mm criteria and LVMI measurements. Postoperative lactate dehydrogenase (LDH) levels were significantly lower than preoperative values in the homograft group, but were significantly raised in the prosthesis group. The more favorable hemodynamic results of the homograft group suggest that the use of these valves in the aortic position has a better hemodynamic effect on ventricular performance.