Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the bile ducts, resulting in cirrhosis and need for liver transplantation and reduced life expectancy. The majority of cases occur in young and middle-aged men, often in association with inflammatory bowel disease. The etiology of primary sclerosing cholangitis includes immune-mediated components and elements of undefined nature. No effective medical therapy has been identified. The multiple complications of primary sclerosing cholangitis include metabolic bone disease, dominant strictures, bacterial cholangitis, and malignancy, particularly cholangiocarcinoma, which is the most lethal complication of primary sclerosing cholangitis. Liver transplantation is currently the only life-extending therapeutic alternative for patients with end-stage disease, although recurrence in the allografted liver has been described. A PSC-like variant attracting attention is cholangitis marked by raised levels of the immunoglobulin G4 subclass, prominence of plasma cells within the lesions, and steroid responsiveness.