The idiopathic inflammatory myopathies (IIM) are a rare group of autoimmune diseases, negatively affecting the lives of an estimated 250,000 people worldwide. Delays in diagnosis often occur owing to a lack of recognition of disease presentation, or misdiagnosis, both of which can lead to muscle atrophy. This new addition to the Oxford Rheumatology Library series focuses on providing a summary of what is currently understood about the epidemiology of myositis, controversies in diagnosis criteria, clinical features, and the current paradigms for treatment and intervention. Designed to bring together the multi-disciplinary involvement of healthcare professionals for IMM patients, this is the first easy-to-navigate guide for the practical management of myositis. This is an essential guide for both physicians and trainees in Rheumatology, Neurology, and Dermatology specialities.