Primary sclerosing cholangitis (PSC) is a chronic, liver disease characterized by bile stasis within bile ducts and liver inflammation and fibrosis. It is thought to be an immune mediated, progressive disorder that eventually develops into liver cirrhosis, portal hypertension and hepatic decompensation, in the majority of patients. How does one follow the activity of this disease? Guidelines do not recommend routine MRCP or ERCP to screen for screening for cholangio or hepatocellular(liver) carcinoma. They do recommend these tests for patients with deterioration in their constitutional performance or worsening liver tests. These patients should have these tests to evaluate for a possible chalangiocarcinoma.