The effects of living donor liver transplantation (LDLT) on the recurrence of autoimmune liver diseases have not been well documented. Genetic similarities may be beneficial to avoid severe rejection but may facilitate the recurrence of autoimmune diseases. Because familial occurrence of autoimmune liver diseases has been documented, there is a possibility that candidates for living-related donors may have the same disease as that of the recipients. Between November 1994 and June 2004, 50 patients with primary biliary cirrhosis (PBC) (16-non-blood-relative donors and 34 blood-relative donors), and 28 patients with primary sclerosing cholangitis (PSC) underwent LDLT in Kyoto University Hospital. Among 35 patients with PBC who survived more than 1 year, 10 patients (29%) showed recurrent PBC, and nine of 10 patients with recurrent PBC (90%) were associated with blood-relative donors (mean follow-up period, 30 months; range, 2-68). Two recipients had donors with some clinical or histological characteristics of PBC, and their grafts developedrecurrent PBC. Cirrhosis or graft failure was not observed in any patients with recurrent PBC. For PSC patients who survived more than 1 year after LDLT, 13 of 22 (59%) showed PSC-compatible histology and radiological findings (mean follow-up period, 31 months; range, 22-71), and five died or underwent retransplantation. Human leukocyte antigen-DR15 was positively associated with susceptibility to PSC with ulcerative colitis. One donor was revealed to have retroperitoneal fibrosis without evidence of sclerosing cholangitis. Blood-relative donors may be associated with susceptibility to recurrent autoimmune diseases. Recurrence of PSC, but not PBC, adversely affected the outcome of LDLT. Caution should be taken as blood-relative donors can be at risk of autoimmune liver diseases.