We report 101 episodes of Kawasaki disease in 100 patients seen over a 12 year period. A total of 35 patients had cardiac involvement ranging from pericardial effusion to coronary artery aneurysms with ischaemic complications, which resulted in death in one patient. Laboratory investigations showed leucocytosis, thrombocytosis, and a raised erythrocyte sedimentation rate to be common features and the first two variables were significantly associated with cardiac involvement. Treatment regimens changed over the study period. Aspirin was used in most patients often in conjunction with dipyridamole and from 1986 intravenous immunoglobulin was given routinely to those patients seen early in the illness. Additional therapeutic measures in individual patients included prostacyclin, heparin, streptokinase, and plasma exchange/exchange transfusion. Attention is drawn to the uncertainity of the long term cardiovascular consequences in the light of adults reported with premature atherosclerotic lesions of similar appearance to those seen in Kawasaki disease.