Purpose: Acute thrombosis of arteriovenous graft (AVG) has been treated by surgical thrombectomy; however, endovascular treatment became an alternative treatment option recently. The purpose of this study is to evaluate the effectiveness of endovascular treatment for acute thrombosis of AVG (EndoAVG) by primary endovascular treatment strategy. Methods: This is a retrospective study of patients who underwent EndoAVG from January 2003 to December 2010 in Inha University Hospital. The patients' clinical characteristics and EndoAVG procedures were reviewed by electronic charts and X-ray films. Clinical success was defined as the residual stenosis below 30% or success of hemodialysis. Results: Thirty-eight patients were enrolled. The mean age was 64±15.4 years in the success group and 58±17.2 years in the failed group. The mean duration from AVG formation to endovascular thrombectomy was 19.2±29.5 months. The success rate of EndoAVG was 84.2% (32/38). There were three complications after EndoAVG: two brachial artery thromboses and one rupture of a vein at the ballooning site. Six months, twelve months and twenty-four months secondary patency rate were 77.5%, 65.5%, and 42.5%, respectively. Conclusion: The success rate of EndoAVG was 84.2%. Its result is compatible with open thrombectomy and can be a good alternative option for the treatment of acute thrombosis of AVG. Larger number of cases is required for stronger study.