BACKGROUND: Few patients with Kawasaki's syndrome have been described in Norway. Different aspects of diagnosis and treatment are assessed in this article. MATERIAL AND METHODS: We retrospectively reviewed 26 cases of Kawasaki's syndrome at Haukeland University Hospital 1985-1999. RESULTS: 85% of the patients fulfilled all criteria for diagnosis and were treated as recommended; yet we found a high frequency of coronary aneurysms (22%). Children with aneurysms had delayed onset of treatment compared to patients without complications. Infants were treated later and had a higher incidence of aneurysms. Laboratory findings differed among infants and older children, and in patients with or without aneurysms. INTERPRETATION: Kawasaki's syndrome is still a clinical diagnosis. Laboratory tests may, however, help to identify patients with high risk of complications. Infants should be followed carefully in the acute phase of febrile illness and be treated early, even when the presentation is atypical. Early adequate treatment is of vital importance to avoid complications and reduce short and longterm morbidity.