The systemic haemodynamic pattern and its changes after at least 6 months of successful percutaneous transluminal angioplasty (PTRA) was evaluated in a group of patients with renovascular hypertension (RVH). Fourteen patients, nine males and five females, aged 21 to 58 years, were studied; 12 had fibrodysplastic and two had atherosclerotic stenosing renal vascular lesions. Seven were cured and seven improved. Hypertension was characterized by increased plasma volume (PV) and total peripheral vascular resistance (TPR). Mean peripheral plasma renin activity (PRA) and 24-h urine aldosterone (UA) were elevated. However, the vasoconstriction did not appear to be related to the increased activity of the renin-angiotensin system. After at least 6 months of a successful PTRA, the fall in blood pressure (BP) was associated with a decrease in TPR; PV appeared normal, and PRA and UA became normal.