The aim of this study was to assess the blood pressure profile and vasoactive hormones in valvular aortic disease. Thirteen aortic stenosis and/or aortic regurgitation patients were matched with 13 control subjects. Ambulatory blood pressure monitoring was performed for 24 h. Arterial and venous plasma concentrations of renin, angiotensin II, aldosterone, arginine vasopressin, atrial natriuretic peptide, immunoreactive endothelin and cyclic-GMP were measured. The mean 24-h blood pressure was higher in the patient group (94.9 mmHg) compared with control subjects (88.2 mmHg) (p < 0.0001), despite no differences in daytime blood pressures. The nocturnal blood pressure fall was attenuated in the patients (systolic/diastolic blood pressure -8.5/-3.5; -20.3/-14.3 mmHg (p < 0.001/p < 0.01)); in heart rate too the nightly fall was blunted in the patients (-4.8/ -13.4/min (p < 0.0013)). PRA, Ang II, AVP, ANP, ir-ET and cGMP were significantly increased in the patients compared to the controls. Nightly systolic blood pressure fall was inversely related to arterial (r = -0.75, p < 0.003) and venous (r = -0.65, p < 0.04) plasma renin activity and arterial aldosterone (r = -0.64, p < 0.05) in valvular aortic disease patients. In conclusion, valvular aortic disease patients have attenuated falls in blood pressure and heart rate during the night. Increased activity in the renin aldosterone system may be involved in this abnormal blood pressure regulation.