Malignant biliary obstruction is often caused by tumour within the biliary tree, or extrinsic compression. This often results in patients becoming jaundiced causing a significant associated morbidity. The majority of malignant biliary obstruction is due to inoperable disease, and therefore the mainstay of palliating jaundice is stent placement at endoscopic retrograde cholangiopancreatography (ERCP). Cross-sectional imaging is necessary to determine if stenting is appropriate and to guide stent placement. This is especially important in patients with hilar cholangiocarcinoma, where drainage should be undertaken in specialist centres. Self-expanding metal stents are preferable to plastic stents and are cost effective if survival is likely to be more than 6 months. With the exception of pancreatic carcinoma, traditional non-operative disease modifying treatments for biliary malignancies have shown only limited benefit. This particularly relates to radio and chemotherapy. Photodynamic therapy is a relatively new modality of treatment that appears to be effective in patients with local but inoperable cholangiocarcinoma and is capable of prolonging survival.