Both immediate and long-term prognosis of Kawasaki's disease (K. D.) are due to cardiac involvement and, particularly, to coronary artery aneurysms formation. Of 19 cases that we studied, age ranging between 7 months and 8 years, 18 has been followed clinically and with echocardiographic procedure. In 1 case (10 years old), which underwent a triple bypass surgical operation due to the presence of multiple aneurysms, diagnosis was made retrospectively. In 2 of 19 cases (10.52%) coronary artery aneurysms were present. One case showed aneurysm's partial regression two years later. In 10 of 18 cases (55.5%) clinical evidence of cardiac compromise was present, whereas in no patient ECG alterations occurred at all. Our data prove the poor benefit of clinical approach and ECG interpretation in K. D., whereas we believe that echocardiographic study is the best method in early identification of aneurysms.