To define the benefits and risks of renal revascularization or nephrectomy in patients with both severe hypertension and chronic renal insufficiency, we analyzed 98 patients who underwent renovascular operations after serum creatinine levels exceeded 2 mg/dl. This subset of patients was selected from a retrospective review of 652 renal operations performed at the Mayo Clinic for renovascular disease between 1970 and 1981. Special attention was given to the type of operations, their effect on hypertension and renal function, specific factors that affected operative deaths, and late survival. Unilateral renal operations were performed in 48 patients with bilateral procedures in 50. Simultaneous aortic reconstruction was necessary in 55 patients (56%). Postoperative diastolic blood pressure was less than 90 mm Hg in 55% of patients and 90 to 100 mm Hg in an additional 33%. Seventy-six percent of patients required less antihypertension medication. Serum creatinine improved or stabilized in 69%. Ninety percent of patients avoided any early or late renal dialysis. The operative mortality rate was 7.1% and tended to be higher in patients with a serum creatinine greater than 3 mg/dl and in those with past myocardial infarction (p = 0.05). The late survival rate was 64% at 5 years. The main cause of operative and late death was myocardial infarction. In conclusion, most patients with renovascular hypertension and early chronic renal insufficiency can be benefited by surgical revascularization or nephrectomy. Future improvement in early and late survival may require a more aggressive approach to the identification and correction of significant coronary artery disease.