Kawasaki disease (KD) is an acute self-limiting systemic vasculitis of unknown aetiology. It is the most common cause of acquired heart disease in young children. The intense inflammatory process has a predilection for the coronary arteries, resulting in the development of aneurysmal lesions, arterial thrombotic occlusion or, potentially, sudden death. There is no specific diagnostic test; however, treatment with immunoglobulin and aspirin effectively reduces cardiac complications from 25% to 4.7% in the UK. Inflammation of the myocardium, endocardium or pericardium can occur early in the disease and endothelial dysfunction along with abnormalities of myocardial blood flow may require continuing medication, interventional catheterisation or even cardiac surgery. Several new pharmacological treatments may have important roles to play in managing KD in children and adolescents. This review discusses the history of the disease, the diagnostic challenges, epidemiology, aetiology, pathology, immunopathogenesis, treatment, genetic influences and the long-term cardiovascular sequelae.