Kawasaki disease (KD) is a medium vessel vasculitis with predilection for coronary arteries. Due to lack of a reliable confirmatory laboratory test, the diagnosis of KD is based on a constellation of clinical findings that appear in a typical temporal sequence. These diagnostic criteria have been modified from time to time and the most recent guidelines have been proposed by the American Heart Association (AHA) in 2017. However, several children may have incomplete or atypical forms of KD and the diagnosis can often be difficult, especially in infants and young children. In this review, we have detailed the steps involved in arriving at a diagnosis of KD and also highlight the important role of echocardiography in diagnosis and management of children with KD.