By using a National Health Insurance database, we investigated the occurrence of Kawasaki disease (KD) shock syndrome in Taiwan. KD shock syndrome occurred most frequently in winter, and the incidence was 1.45 per 100 patients with KD. Compared with KD patients without shock, KD shock syndrome patients were older, more likely to develop coronary lesions (15.9% vs. 7.0%) and had longer hospitalization duration.