Mixed Connective Tissue Disease (MCTD) is a complex clinical entity, which includes features of Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA), Systemic Sclerosis (SSc) and Polymyositis/Dermatomyositis (PM/DM), along with the presence of a distinctive antibody, anti-U1-Ribonucleoprotein (RNP). Autoimmune hepatitis is a chronic inflammatory disease of the liver. It is characterized by increase in transaminase and immunoglobulin G levels, the presence of autoantibodies, and portal inflammatory infiltrate with interface hepatitis at liver biopsy. Primary biliary cholangitis is a chronic inflammatory autoimmune liver disease that is characterized by a positive antimitochondrial antibodies test and consequent progressive destruction of the small intrahepatic bile duct. Many reports have confirmed the development of autoimmune diseases after SARS-CoV-2 infection.Here we report the case of a 64-year-old woman, with a positive medical history for SARS-CoV2 infection, who was admitted to our Internal Medicine Unit “Cesare Frugoni”, Policlinico Hospital, Bari, in January 2022, and diagnosed with an extremely rare Multiple Autoimmune Syndrome (MAS), consisting in Mixed connective tissue disease, autoimmune hepatitisand primary biliary cholangitis.