PURPOSE: To determine the effectiveness and patency of percutaneous intervention in insufficient native arteriovenous hemodialysis fistulae (AVFs). MATERIALS AND METHODS: Between March 1997 and September 2001, 67 cases of insufficient native AVF in 56 patients were treated by endovascular intervention. Except eight cases of insufficient native AVFs resulted from central vein lesion, PTA was performed in 48 cases, and thrombolytic therapy with or without PTA in 11. In eight of the cases, in which central vein stenosis had led to the insufficency, percutaneous transluminal angioplasty (PTA) was performed, and in three of the eight, a stent was inserted. Angiographic findings and complications, as well as success and patency rates in the non-thromobosis and thrombosis group, were evaluated; the central vein lesion group was analysed separately. RESULTS: Among 84 lesions observed at angiography, there were 54 cases of stenosis, 17 of occlusion, and 13 of combined thrombosis. The lesions were located in a proximal vein (n=51), distal vein (n=14), artery (n=6), and at the site of anastomosis (n=13). In the central vein lesion group (n=8), seven cases of stenosis and one of occlusion were noted. The overall procedural success rate was 79.1% (53/67). That is, in patients with no central vein lesion, the procedural success rate of PTA of native AVFs was 85.4% (41/48) and the patency rates of this were 83.1% at 6 months and 67.4% at 12 months. In cases of thrombolysis with/without PTA, the procedural success rate was 54.5% (6/11) and the patency rates were 83.3% at 6 months and 62.5% at 12 months. Finally, in patients with a central vein lesion, the procedural success rate was 75% (6/8) and the patency rates were 80% at 6 months and 30% at 12 months. There was one case of pseudoaneurysm formation at the puncture site of the brachial artery, which was used as the access route for intervention; one embolism in the brachial artery; and three cases of vascular spasm and two of hematoma which did not require active treatment. CONCLUSION: Percutaneous intervention offers effective and safe management of insufficient AVFs. The procedural success rate was higher for stenosis than for thrombotic occlusion.