The aim of this study was to assess the prevalence clinical presentation, and impact on outcome of late hepatic artery thrombosis (HAT) after OLT. We also sought risk factors other than technical problems that predispose to the pathogenesis of late HAT among 178 OLT performed from 1999 to 2002. Late HAT was diagnosed using Doppler ultrasonography and arteriography. Late HAT was observed in nine patients (3.8%), all of whom had experienced chronic HCV infection. Median time to HAT diagnosis was 4.88 months after OLT. Mean follow-up time was 40.25 months. Recipient age ranged from 30 to 61 years and median donor age, 28 years. Mean warm ischemia time was 63 minutes and mean cold ischemia time, 660 minutes. All of our study group were cigarette smokers. Postoperative CMV infection, presenting with hepatitis, had been treated in 55.6%. Before the diagnosis of HAT more than one episode of acute cellular rejection had been observed in six patients (55.6%) and 44.5% had chronic rejection. The diagnosis of CR was established after the diagnosis of HAT in all cases. Recurrence of HCV infection was histologically documented in 44.5%. Only one patient experienced graft loss (77 months after OLT). Six of nine patients had biliary complications, treated either by endoscopic stenting or by surgical drainage. Two patients were asymptomatic. In conclusion, late HAT shows a benign presentation that has no impact on graft survival. Possible risk factors have yet to be defined by multicenter trials.