This paper reports the results of reconstructive renal arterial operations on 23 patients who underwent surgery because it was considered that renal artery disease was contributing to their chronic renal failure. The median pre-operative serum creatinine in this group of patients was 0.77 (range 0.15-1.14 mmol/l) and all patients had severe hypertension. In 10 cases there was evidence of other renal disease (analgesic nephropathy, 8; glomerulonephritis, 2). Operation performed was unilateral aortorenal reconstruction in 21 patients and bilateral reconstruction in 2 patients. There were four in-hospital deaths. In 15 patients operation was judged to have improved their renal function with a fall of median pre-operative creatinine from 0.34 mmol/l (0.15-0.84) to a median creatinine of 0.15 (0.05-0.52). There was one intra-operative death. There were 7 patients in whom operation led to no improvement in renal function. Their median pre-operative creatinine was 0.90 (0.32-1.14 mmol/l), and this pre-operative creatinine differs significantly from the group whose creatinine fell after surgery (P less than 0.002). Renal artery reconstruction should be considered in patients with chronic renal failure who have correctable arterial lesions.