Primary biliary cirrhosis is predominantly seen in middle-aged women. Typical symptoms are fatigue, pruritus, and abdominal pain. Jaundice develops in the endstage disease. At presentation, about 40% of the patients are asymptomatic, but 30% to 50% already have hepatomegaly, and 15% present with splenomegaly. Even patients with fully developed liver cirrhosis may be free of symptoms. Abnormal physical signs and advanced histological stage are more frequent in symptomatic than in asymptomatic patients. Fatigue, pruritus, and Sjögren's syndrome are more common in women than men, but other signs and symptoms do not differ in the two sexes. PBC is associated with a large variety of other diseases, like arthropathy, CREST syndrome, autoimmune thyroiditis, and so on, which in addition will or will not produce symptoms. Hepatocellular carcinoma is a rare complication in women, but more frequent in men. Diagnosis can be established by the triad antimitochondrial antibodies (AMA), cholestatic indices, and liver histology, diagnostic or compatible with PBC. When AMA are not detected, then antinuclear antibodies (autoantibodies against gp.210 and others) can be detected in 50% of AMA-negative patients. AMA titers do not correlate with the course of the disease nor histological progression. After liver transplantation, AMA recur in nearly 100%. The liver enzyme pattern in PBC patients is cholestatic: alkaline phosphatase and gammaglutamyltransferase increase to 10 or more times the upper limit of normal. The amount of enzymes does not correlate with disease progression or stage of the disease. The only prognostic factor in PBC is serum bilirubin. AMA-negative patients account for about 10% to 15%. Routine biochemical tests are not different from AMA-positive patients, but usually higher ANA, SMA, and IgG concentrations are detected. Histologically, it is PBC. The overlap-syndrome, autoimmune hepatitis-PBC presents with the histological features of autoimmune hepatitis and PBC, with AMA, ANA, or SMA. Imaging procedures are not helpful for the diagnosis of PBC, except for liver histology. Histologically, four different stages can be assessed, ranging from florid bile duct lesions, ductular proliferation, and fibrosis to liver cirrhosis. Liver histology is of interest for the assessment of the diagnosis and for staging of the disease.