In this study the effects of percutaneous transluminal renal angioplasty on blood pressure and renal function were studied in 9 hypertensive patients with stenosis of the main artery of a solitary functioning kidney. The outcome of the percutaneous dilatation of the renal artery stenosis, and the effects on blood pressure and renal function were evaluated for a mean period of 16.4 ± 2.13 (SE) months (ranging from 3 to 65 months). A successful dilatation of the renal artery stenosis was shown in all the patients by the aortography performed 1 h after the procedure. At the discarge (7.8 ± 0.9 days after dilatation), blood pressure was ‘cured’ in 2 patients and ‘improved’ in the remaining patients; renal function was improved in all patients who had reduced renal function. At the last follow-up, no restenosis was found in patients who repeated the follow-up angiography; blood pressure was ‘cured’ in 3 patients and ‘improved’ in 6 patients, and renal function appeared steadly improved. In contrast with other reports, our results demonstrate that percutaneous renal angioplasty is a safe and effective procedure and should be attempted before considering surgical intervention in patients with artery stenosis of a solitary functioning kidney.