The headword "overlap syndromes" of liver diseases includes the coexistence of autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis. These syndromes often represent a diagnostic and therapeutic challenge for hepatologists; it remains unclear whether these overlap syndromes form distinct entities or they are only variants of the major autoimmune liver diseases. The most frequent reported association occurs between autoimmune hepatitis and primary biliary cirrhosis, whereas the overlap between autoimmune hepatitis and primary sclerosing cholangitis is less frequent, typically at young age and often attendant with an inflammatory bowel disease. The choice therapy is based on ursodeoxycholic acid and immunosuppressive drugs, used at the same time or consecutively, according to the course of disease. The diagnostic scores for autoimmune hepatitis can help for diagnosis, even though their definitive soundness is lacking.