This book aims to raise awareness of IgG4-related sclerosing cholangitis among practicing physicians and to equip readers with a sound understanding of the principles of diagnosis and treatment. Clinical, serological, and histopathological features are clearly described and imaging appearances on all relevant modalities are illustrated, covering the bile duct and other involved organs. Differential diagnosis from other diseases, including primary sclerosing cholangitis and cholangiocarcinoma, is precisely explained. Information is then presented on all significant current and emerging therapeutic strategies, including steroids, immunosuppressive drugs, and rituximab. Finally, attention is drawn to significant prognostic features. While IgG4-related sclerosing cholangitis is now a widely acknowledged condition, most practitioners are still liable to misdiagnose it owing to a lack of familiarity with its presenting features.