We compared the efficacy and safety of percutaneous transluminal renal angioplasty for the treatment of renovascular disease in 66 patients. Thirty-four were aged less than 60 years, and 32 more than 60 years. The younger patients had a shorter known duration of hypertension and higher levels of diastolic pressure (6.4 +/- 9 years and 109 +/- 15 mmHg) than the older patients (12.8 +/- 8 years and 101 +/- 11 mmHg, P less than 0.01 for both comparisons). They also had higher creatinine clearance rates (78 versus 46 ml/min, P less than 0.01) and less severe renal artery disease. A total of 70 percutaneous transluminal renal angioplasties were performed in 70 arteries with a technical success rate of 100% in the younger group versus 67% in the older group (P less than 0.01); complications occurred more frequently in the older group. Our data indicate that, when technically successful, percutaneous transluminal renal angioplasty improves blood pressure to a similar extent in both younger and older patients. However, in patients over 60 years, the safety of the procedure is limited by more severe age-associated atheroma of renal and extrarenal arteries.