Background. In hemodialysis patients the most common cause of vascular access failure is neointimal hyperplasia of vascular smooth muscle cells at the venous anastomosis of arteriovenous fistulas. Case report. We presented a 76-year old patient who had developed fistula thrombosis without the presence of known risk factors the eighth day after the initial function. A histopathological finding pointed to a significant rate of neointimal proliferation, as an initial reasons for the fistula stenosis and trombosis. Conclusion. Early pathohistological changes observed in ateriovenous fistula dysfunction are response to hemodynamic changed conditions.