In hypertensive patients with hypertrophy, abnormal peak filling rate (PFR) is related to a decline in left ventricular (LV) ejection fraction (EF) during supine exercise. Because an increased LV preload is more common during upright exercise, we determined this relation during upright and supine exercise. In 20 hypertensive patients, rest and exercise radionuclide angiography in the supine and upright positions, as well as echocardiography, were performed and compared with 20 age-matched controls. At rest in the supine and upright positions, blood pressure, LVEF, and PFR were 164±20/94±10 and 164±24/94±10mm Hg, 65±8% and 65±6%, and 2.77±0.59 and 2.70±0.52 end-diastolic volumes/s, respectively. PFR was reduced compared with controls (3.29±0.3 and 3.27±0.27 end-diastolic volumes/s, supine and upright). LV mass index was normal (94±19 g/m²). LVEF increased during upright but not during supine exercise in the hypertensives. Four patients had a decline in each position versus none of the controls. There was no relation between the change in LVEF and rest PFR. In patients with mild to moderate hypertension without extensive hypertrophy, abnormal filling rales were present but did not correlate with the change in LVEF with exercise.