Purpose: We sought to determine recent trends in the incidence and epidemiologic features of Kawasaki disease (KD) in Ontario and Canada. Methods: A survey for incident cases from 1998-2000 was performed for all hospitals and pediatric cardiologists in Ontario. In addition, national hospital discharge abstract data from the Canadian Institute for Health Information (CIHI) was related to population denominators from census data from Statistics Canada. Results: Our previous epidemiologic survey identified an annual incidence for 1995-1997 of 14.5 per 100,000 children aged <5 years in Ontario. This contrasts with an incidence of 18.9 derived from CIHI data for the same period (diagnoses not verified). From the current Ontario survey for 1998-2000, 634 incident cases were identified (67% males), for an annual incidence of 20.6 per 100,000 children aged <5 years. Cases were typical in 82% (50% with coronary involvement), with 7% having fewer than 5 criteria but with coronary involvement (atypical), and 11% having fewer than 5 criteria and no involvement (incomplete). Coronary aneurysms were noted in 4.1%, only 54% of whom had typical KD. IVGG was given in 88%, and within 10 days of fever onset in 93%. Median length of stay for hospitalized cases was 2 days (range, <1 to 15), and was not related to age, number of criteria, timing of IVGG treatment or coronary complications. From CIHI data for 1994-1998 for Canada, a significant trend towards peaks in December and January, with a lesser peak in June, was noted (p<0.001), with no significant differences in seasonal trends between years. From CIHI data for 1979-1998, there was a significant linear increase in annual incidence (p<0.001) which was greater in males (0.84 per year) vs. females (0.47 per year; p<0.001). Conclusion: An increasing incidence is noted, which may reflect contributions of increasing physician awareness and an increased diagnosis of atypical and incomplete cases.