AIMS: ADA guidelines recommend aspirin for all patients with diabetes who have had a prior CHD events as well as a primary prevention strategy among those with at least one other risk factor. We examined the current status of regular aspirin intake among Korean adults who diagnosed as diabetes. METHODS: This study examined the characteristics of aspirin user in new-onset diabetes over 40 years based on health insurance claims submitted to the Health Insurance Review Agency (HIRA) of Korea during the period from January 2001 through December 2003. New onset diabetes defined as the first health insurance claim of antidiabetic drugs submitted to HIRA for the three months (January to March 2001) that never submitted for previous 6 years. RESULTS: The number of total new-onset diabetic patients was 30,014 in 2001, 29,819 in 2002, and 32,061 in 2003. The incidence rate of diabetes over 40 years for 3 months in 2001, 2002 and 2003 were 0.172%, 0.167% and 0.18. Mean age of women who diagnosed diabetes were significant higher than that of men in 2001 (women 59.2+/-10.6 yrs, men 54.8+/-9.8 yrs), in 2002 (women 59.5+/-10.6 yrs, men 54.6+/-9.3 yrs) and in 2003 (women 59.6+/-10.7 yrs, men 54.7+/-9.9 yrs) (p < 0.001). The number of aspirin user increased from 2,065 (6.9%) in 2001, 2,638 (8.9%) in 2002 and 3,711 (11.6%) in 2003. 30.5% of new-onset diabetics in 2001 had hypertension, 12.4% of them had hypercholesterolemia, 11.8% of them had cerebral infarct, 2.6% of them had cerebral hemorrhage, 3.8% of them had coronary heart disease and, but, 55.6% of them had not any CVD. Logistic regression analysis using aspirin use as a dependent variable showed that the number of aspirin use in patients with hypertension, hypercholesterolemia, cerebral infarct and coronary heart disease was higher than in patients without those (hypertension [OR], 3.89 (95% CI, 3.52~4.31); hypercholesterolemia [OR], 2.16 (95% CI, 1.90~2.46; cerebral infarct [OR], 2.05 (95% CI, 1.82~2.30); coronary heart disease [OR], 9.41 (95% CI, 8.20~10.80), respectively). Coronary heart disease was the most important associated factor of aspirin use. CONCLUSIONS: We found significant underuse of aspirin therapy among our population compared with that of America. Major efforts are needed to increase aspirin use in diabetic patients.