Background: Chronic kidney disease (CKD) is a powerful risk factor for development of cardiovascular disease (CVD). Previous trials have investigated the effect of low dose aspirin on prevention of CVD in patients with diabetes but not in CKD patients. In addition, the role of aspirin in diabetics is controversial and the available literature is contradictory. Therefore, we studied whether low dose aspirin would be beneficial in patients with chronic kidney disease (CKD) as high risk group for CVD. Methods: Using propensity score matching, 1884 low dose aspirin (100mg/day) recipients and 1884 non-recipients were 1:1 paired for analysis from 25340 patients with CKD. The primary endpoint was atherosclerotic CVD including coronary arterial disease, stroke, and peripheral arterial disease. Secondary endpoints included death from any cause, bleeding events, doubling of serum creatinine and renal death. Results: The incidence of primary endpoint of any atherosclerotic CVD was significantly higher in the aspirin users than in the non-aspirin users (p<0.001). Secondary endpoints including all-cause mortality, composite bleeding events were not significantly different between the aspirin and non-aspirin users. However, the occurrence of a doubling of serum creatinine concentration (p=0.001) and renal death (p=0.042) were significantly associated with the use of aspirin. Conclusion: These results suggest that use of low-dose aspirin in patients with CKD has a possible harmful effect on CVD and renal progression.