Kawasaki syndrome is an acute, self-limited vasculitis that occurs in children of all ages and presents a challenge for the clinician: the disorder can be difficult to recognise; there is no diagnostic laboratory test; there is an extremely effective therapy; and there is a 25% chance of serious cardiovascular damage if the treatment is not given early in the course of the disease. This review includes discussion of the history of the syndrome, the diagnostic challenges, epidemiology, aetiology, pathology, immunopathogenesis, therapy, genetic influences, and the long-term cardiovascular sequelae.