Transplant renal artery stenosis is a potentially treatable cause of post-transplant hypertension. Transluminal angioplasty under radiological control facilitates treatment, and in this study the results of 15 consecutive patients treated in one department have been analysed to assess the safety and success of the technique, blood pressure control and transplant function. Technical success was achieved in 14 patients (93%), with zero mortality and only 1 major complication requiring surgical intervention. Blood pressure control was significantly improved by angioplasty, mean blood pressure (diastolic + 1/3 pulse pressure) being lower 4-6 weeks later (P less than 0.05) and a mean of 34 months later (P less than 0.01), and transplant renal function was unaffected. In the treatment of transplant renal artery stenosis percutaneous transluminal angioplasty is effective, safe and often of lasting benefit.