Liver transplantation is complicated by specific medical problems. Diabetes mellitus occurs in 4-20% of patients undergoing liver transplantation. Patients with primary sclerosing cholangitis and ulcerative colitis experience up to a 13% incidence of colon cancer after transplantation. Lymphomas occur in 1-3% of patients after transplantation and account for 57% of malignancies occurring in adult patients. Atraumatic bone fractures occur in 22-38% of patients and neurological complications, including seizures, headache, and neuropathy occur in 19-47% of patients following liver transplantation. Patients undergoing liver transplantation may experience recurrence of their primary liver disease: hepatitis B, hepatitis C, primary biliary cirrhosis, autoimmune hepatitis, or primary sclerosing cholangitis. In patients not receiving immunoprophylaxis after transplantation for chronic hepatitis B, recurrent hepatitis B is seen in up to 90% of patients. This can be markedly reduced with hyperimmune globulin immunoprophylaxis. Recurrent hepatitis C is seen in the majority of patients; current treatment modalities are inadequate. Recurrence of primary biliary cirrhosis or primary sclerosing cholangitis in the allograft is infrequent. Autoimmune hepatitis may recur in up to 26% of patients following liver transplantation. Primary disease recurrence in the allograft and preventive strategies are discussed.