Insertion of a fully covered self-expandable metallic stent (FCEM) through endoscopic retrograde cholangiopancreatography is an effective solution for biliary anastomotic stricture following orthotopic liver transplantation (OLT). However, FCEM migration continues to plague patients. This study aimed to evaluate the FCEM migration rate in our center, and to investigate the factors increasing the migration risk for FCEM.The study enrolled 43 post-OLT patients with confirmed duct-to-duct AS. The effects of age, gender, albumin, alanine aminotransferase, aspartate aminotransferase (AST), γ-glutamyl transpeptidase, alkaline phosphatase, total bilirubin, direct bilirubin, ABO (blood group system consists of four antigens) incompatibility, stricture length, FCEM brand, FCEM length, donor liver and recipient bile duct diameters, size mismatches between the donor and recipient bile ducts >2 mm, diabetes and/or hypertension status, endoscopic sphincterotomy status, the use of plastic stents or nasobiliary drainage prior to FCEM implantation, duration from OLT to FCEM placement, and OLT etiology on FCEM migration were retrospectively analyzed.The FCEM migration rate was 48.8% (21/43) at 6 months. The serum AST level was significantly higher in the migration group than that in the nonmigration group (52.48 vs 29.50 U/L, P < .05). A lower serum AST level was associated with a decreased risk of FCEM migration in post-OLT patients with duct-to-duct anastomotic stricture (hazard ratio = 0.968, 95% confidence interval: 0.940–0.996, P = .028).In this single-center, retrospective cohort study, we showed that an elevated serum AST level was a potential risk factor for FCEM migration.