A hypertensive response to exercise (HRE) is known to be associated with higher risk of heart failure and future cardiovascular events in patients with hypertension. Left atrial volume index (LAVI) is associated with the diastolic dysfunction, indicating exercise intolerance. Therefore, we investigated whether LAVI is relevant to HRE during cardiopulmonary exercise test (CPET). We studied 118 consecutive hypertensive patients (61 men, 57±11 years) and 45 normotensive control subjects (16 men, 54±8 years). Clinical characteristics, CPET, echocardiographic and laboratory findings were assessed at the time of enrollment. HRE was defined as maximum systolic blood pressure (SBP)⩾210 mm Hg in men and ⩾190 mm Hg in women. HRE was more prevalent in hypertensive patients compared with normotensive control subjects (50.8% vs. 20.0%, P<0.001). Age and baseline SBP were shown to be associated with HRE in normotensive control subjects, as were baseline SBP and LAVI in hypertensive group. In multivariate analysis, LAVI was found to be an independent predictor of HRE in hypertensive patients (P=0.020) but not in normotensive control subjects (P=0.936) when controlled for age, sex, body mass index and peak oxygen consumption. Higher LAVI, reflecting the duration and severity of increased left atrial pressure is independently associated with HRE in hypertensive patients, but not in normotensive control subjects.