This issue of Rheumatic Disease Clinics provides important updates in myopathies. The following essential topics are covered: clinical features, pathophysiology, and treatment of polymyositis and dermatomyositis; inclusion body myositis; metabolic myopathies; drug-induced myopathies; muscular dystrophies and neurologic diseases; laboratory testing and imaging; electrophysiological studies; metabolic and genetic testing; and pathology.