Two girls were diagnosed with Langerhans cell histiocytosis (LCH) at the age of 16 and 7 months and developed end stage chronic liver disease related to LCH-induced sclerosing cholangitis at 28 and 8 months, respectively. They received liver transplants at 34 and 14 months of age. Five months post-orthotopic liver transplantation (OLT) one of the patients developed posttransplant lymphoproliferative disease, successfully treated with a combination of surgery and reduction of immunosuppression. Fourteen months post-OLT she developed diabetes insipidus, bilateral ear discharge, and new osteolytic lesions. After transplantation both girls had mild skin reactivations of LCH, requiring minimal steroid increments. At 60 and 5 months post-OLT intrahepatic LCH recurrence was diagnosed on the basis of abnormal biliary enzymes and presence of Langerhans cells in the grafts. Initial cholangiography in both patients was unremarkable. LCH activity was controlled by maintenance chemotherapy with vinblastine, etoposide, and prednisolone. Ten months after reappearance of LCH in the liver graft a follow-up cholangiography in one of the girls demonstrated a low grade cholangiopathy. Residual elevation of liver enzymes probably represents an ongoing pathogenic process.