In aortic stenosis, gender and other differences in the adaptive remodeling of the left ventricle have been described, but the influence of left ventricular (LV) geometry on systolic function is not widely appreciated. This study tested the hypothesis that the increased ejection fraction seen in some elderly women with aortic stenosis is due to changes in LV geometry, not increased myocardial mass or enhanced myocardial function. We therefore investigated gender-related differences in LV and myocardial function by analysis of end-systolic circumferential stress versus shortening relations in 65 patients (29 men and 36 women) with aortic stenosis who underwent cardiac catheterization and echocardiography. Despite similar degrees of aortic stenosis, there were significant differences between men and women with regard to LV geometry and function. When compared with men, women had higher peak LV pressures (205 ± 27 vs 188 ± 27 mm Hg, p < 0.01), higher ejection fractions (66 ±14% vs 57 ± 18%, p < 0.05), smaller LV end-diastolic dimensions (43 ± 8 vs 51 ± 6 mm, p < 0.01) and higher relative wall thickness (0.66 ± 0.27 vs 0.50 ± 0.10, p < 0.01). LV mass was similar in the 2 groups. Mean values for stress were lower in women and there was a predominance of women at extremely low levels of stress; this subgroup had very high values for relative wall thickness and endocardial shortening, but overall stress-shortening relations were normal. In contrast to chamber function (i.e., endocardial shortening), myocardial function was depressed compared with age-matched control subjects; the midwall shortening analysis, however, showed no difference in circumferential shortening between men and women. Differences between endocardial and midwall shortening were directly related to differences in relative wall thickness. Thus, exaggerated endocardial fractional shortening and high ejection fraction in elderly women with aortic stenosis is due to alterations in LV geometry, not increased LV mass or enhanced myocardial function.