BACKGROUND: Progressive familial intrahepatic cholestasis type 1 (PFIC-1) is a genetic cholestatic disease causing end-stage liver disease, which needs liver transplantation (LT). Simultaneous biliary diversion (BD) was recommended to prevent allograft steatosis after transplantation, while increasing the risk of infection. Here, an attempt was made to perform BD using appendix to prevent bacterial translocation after LT. CASE SUMMARY: An 11-month-old boy diagnosed with PFIC-1 received ABO compatible living donor LT due to refractory jaundice and pruritus. His mother donated her left lateral segment with a graft-to-recipient weight ratio of 2.9%. Internal BD was constructed during LT using the appendix by connecting its proximal end with the intrahepatic biliary duct and the distal end with colon. Biliary leakage was suspected on the 5 CONCLUSION: Internal BD using appendix during LT is effective in preventing allograft steatosis and post-transplant infection in PFIC-1 recipients.