OBJECTIVE To report the 5-year results from the prospective randomized Vienna-2 trial, which was designed to evaluate the safety and effectiveness of adjunctive endovascular brachytherapy (EBT) compared with no further treatment after successful revascularization in patients with long-segment femoropopliteal lesions. METHODS Each patient gave written informed consent to participate in the study, which was approved by the hospital's ethics committee. One hundred two patients (men, 53.9%; mean age, 72.1 years +/- 8.7 [standard deviation]; lesion length, 8.1 cm +/- 4.9) underwent percutaneous transluminal angioplasty (PTA) without further stent implantation. Patients were then assigned to either receive EBT (n = 51) by using an iridium 192 source, with a prescribed dose of 12 Gy at 3 mm from the source axis, or no further treatment (n = 51). Radiation was delivered without a centering catheter. Data were analyzed by using a Student t test for continuous values and a chi(2) test to compare categorical values. A Cox proportional hazards regression analysis was performed to evaluate predictors of recurrence at follow-up. RESULTS After 6 months, the restenosis rate for the 102 patients with completed 5-year follow-up was significantly reduced for the PTA plus EBT group versus the PTA alone group (29.4% vs 56.9%, P < .05). During follow-up we observed a late catch-up phenomenon, and after 5 years the recurrence rate was comparable in both groups (72.5% vs 72.5%, P > .99). Time to recurrence, however, was significantly delayed in the PTA plus EBT group (17.5 months +/- 14.7 vs 7.4 months +/- 6.8 for the PTA alone group, P < .05). CONCLUSIONS At 5-year follow-up, PTA followed by gamma radiation EBT with a dose of 12 Gy resulted in a delay but not an inhibition of restenosis when compared with that of PTA alone.