The Overlap syndrome is characterized by a combination of the major hepatobiliary autoimmune diseases such as autoimmune hepatitis, primary biliary cirrhosis and primary sclerosing cholangitis. It is frequently accompanied by inflammatory bowel disease. Chronic lymphoplasmacellular osteomyelitis is characterized by recurrent episodes of bacterial osteomyelitis and is associated with autoimmune diseases (especially inflammatory bowel disease). We report the case of a girl who was diagnosed with ulcerative colitis and autoimmune hepatitis at 4 years of age and with the overlap syndrome with primary sclerosing cholangitis at 6 years. At 9 years, she was diagnosed with chronic lymphoplasmacellular osteomyelitis.