Hypertension appeared to be related to stenosis of the hypogastricrenal artery system in 5 patients among 153 recipients of renal allografts. Renin assay and arteriography were crucial in the comprehensive evaluation of patients whose hypertension was not clearly related to rejection or excessive sodium intake. Hypereninemia was persistent in 4 of the 5 patients. Stenoses of the transplant renal arteries in three patients were caused by extensive intimal plaque formation. In one patient, periarterial fibrosis caused reduction of flow; 180 degrees torsion of the anastomosis resulted in stenosis in the fifth patient. Surgical correction is difficult and may be facilitated by a transabdominal approach. Vein bypass is probably preferable to patch angioplasty for intimal lesions. Following operation, hypertension was ameliorated and function improved in all patients. Rejection, which has been suggested as one of the causes of intimal plaque formation, ultimately led to the loss of the transplant in one patient. Function is normal in two patients; two patients have evidence of chronic rejection. No effort should be spared to evaluate this special group of patients whose transplant function can predictably be prolonged by decisive surgical management. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7.