Percutaneous transluminal angioplasty (PTA) was eventually successful in a patient with renal artery stenosis due to neurofibromatosis. Although the immediate postangioplasty appearance showed little improvement, the residual stenosis has completely resolved at 5 months. Delayed response to PTA has been previously documented in other types of vascular disease. Its occurrence in renal artery stenosis due to neurofibromatosis emphasizes the importance of long-term follow-up and may be a factor in the poor short-term results that some have reported for PTA in patients with this condition.