Biliary casts are uncommon but are more frequently described in liver transplant patients. To our knowledge there have been only two published cases describing biliary casts in non-liver transplant patients. The aetiology of cast development is not fully known but is likely to be multifactorial with the presence of biliary sludge being a prerequisite for cast formation. Bile duct damage and ischaemia, biliary infection, fasting, parenteral nutrition, abdominal surgery and possibly other factors, are all thought to be implicated in cast pathogenesis via sludge development. Endoscopic management has been shown to be effective in a minority of cases and may act as a temporary measure in others but surgical removal of casts is usually necessary. With a greater understanding and improvement in liver transplant surgical techniques and the management of post-operative complications, the development and severity of biliary sludge and casts have decreased.