Background: Diagnostic arteriography and balloonangiopasty of failing or nonmaturing access is based on usingnephrotoxic contrast. Patients not yet on dialysis withnonmaturing AV accesses or ones with an allergy to contrastmedia represent therapeutic challenge. The aim of the presentstudy is to investigate the safety, feasibility, efficacy, and longtermpatency rate of duplex guided percutaneous trransluminalangioplasty (PTA) in failing and nonmaturing native arteriovenousfistulasMethods: 40 patients with 40 dysfunctional autogenousfistulas (32 with failing and 8 with failing to mature AVFs) weresuitable for the study. They were divided into 2 groups, the 1stgroup (30 patients) treated by balloon angioplasty under duplexguidance, and the 2nd group (10 patients) (control group) treatedby balloon angioplasty that was guided angiographically. Thesuccess rate and long-term patency were assessed.Results: the procedure success rates for duplex guided PTAwere 76.7% (23/30) and 90% (9/10) for aniographically guidedPTA. In all, successful cases the access used immediately forhemodialysis. The patency rates of salvaged AVFs were 100%,91%, 82%, 73%, 61%, 52% and 44% at 1, 3, 6, 9, 12, 15, and 18months respectively.Coclusion: angioplasty of failing AVF can be performedunder duplex guidance which offers very important advantages ofhemodynamic evaluation for recoiling and and avoidance ofcontrast use for repair of malfunctioning AV access in patientswith renal failure not yet on dialysis or in case of allergy.