Non-anastomotic biliary stricture (NAS) formation is a major complication of liver transplantation. We prospectively determined the time to development of responsiveness to treatment, and clinical outcomes following NAS formation. In addition, an extensive analysis of the association of recipient, donor, and clinical variables with NAS formation was performed. A total of 749 consecutive patients was studied in a prospective, protocol-based fashion. Seventy-two patients (9.6%) developed NAS at a mean of 23.6 +/- 34.2 weeks post-transplantation. Non-anastomotic biliary stricture formation resolved in only 6% of affected patients. Although patient survival was not affected, retransplantation and graft loss rates were significantly greater in recipients who developed NAS. In contrast to previous reports, a pretransplant diagnosis of HCV was associated with a low frequency of NAS formation. The incidence of NAS was independently associated with pretransplant diagnoses of PSC and autoimmune hepatitis. Hepatic artery thrombosis, and prolonged warm and cold ischemia times were also independent risk factors for NAS formation. We conclude that NAS developed in approximately 10% of primary liver transplant recipients. A pretransplant diagnosis of autoimmune hepatitis has been identified as a novel independent risk factor for NAS formation. Development of NAS significantly attenuates graft but not patient survival.