BACKGROUND Dialysis vascular access complications are considered as significant causes of morbidity in chronic hemodialysis patients. OBJECTIVE The aim of the present study was a comparison of axillary loop and straight grafts patency and its complications in hemodialysis access. METHODS In this cohort study conducted at Shahid Beheshti Medical University, 77 patients who underwent placement of loop or straight access grafts were included. Demographics, primary and secondary patency rates and complications like thrombosis, infection, bleeding, steal syndrome and other complications were compared in these two groups. The collected data was analyzed by chi-square test, t-test, and logistic regression. RESULTS Primary patency rate in straight and loop groups after 1 month were 88.9% and 92.3% respectively (P = 0.721), and after 24 months were 31% and 55.5% respectively (P = 0.058). Secondary patency rate in straight and loop groups after 3 months were 75.6% and 92.3% respectively (P = 0.189), and after 24 months were 37.9% and 66.7% respectively (P = 0.044). The frequency of complications were the same among two methods of graft replacement and mal incidence of thrombosis, infection, delayed infection, pseudoaneurysm formation and steal syndrome occurrence ultimate graft failure and venous hypertension were not significantly different (P > 0.05). CONCLUSIONS Polytetrafluorethylene (PTFE) vascular graft seems to be an appropriate vascular access and is a promising alternative when upper extremity arteriovenous fistulas cannot be constructed. Additionally, there was no significant difference between the two groups for complications and early patency, but late patency was improved in loop group. More study is necessary for a conclusive assessment.