Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease that predominantly occurs in middle-aged women of various ethnic and racial populations. The disease slowly progresses over decades and is supposed to be caused by immune reactions against host antigens. Histologically, it is characterized by inflammatory destruction of intrahepatic small bile ducts, subsequent fibrosis, and finally liver cirrhosis. It is more frequently diagnosed now than in the past probably because of a greater awareness of the disease. There is only week association of PBC with genetic markers. Liver function tests reveal an elevation of serum alkaline phosphatase and gamma-glutamyl transpeptidase levels with or without elevated aminotransferase levels. The hallmark of the disease is the presence of antimitochondrial antibodies (AMAs), which are found in 95% of patients with PBC. AMAs have been shown to be directed against the 2-oxo-acid dehydrogenase complexes located on the inner membrane of the mitochondria. However, AMA titers do not correlate with the disease severity of progression, and the role of AMAs in the pathogenesis of PBC has not been shown. The disease is frequently associated with other autoimmune diseases, including Sjögren's syndrome, scleroderma and thyroid disorders. Most therapeutic efforts have been directed at altering the immune response. Ursodeoxycholic acid (UDCA) appears to be effective therapy in preventing or delaying the need for liver transplantation and improving survival. However, a number of patients receiving UDCA still develop progressive disease and go on to transplantation, which is an effective therapy at the end stage of the disease. Various prognostic models have been proposed to estimate the survival probability and assist in the determination of the optimum timing of liver transplantation.