OBJECTIVES: This study aims to identify whether it is desirable to recommend low-dose aspirin as chemoprevention therapy for colorectal cancer in addition to routine screening through cost-effectiveness review for general population in Korea. METHODS: A Markov model was constructed to simulate the disease natural history of colorectal cancer with routine screening and additional chemoprevention by low dose aspirin. The model evaluated hypothetical cohorts of each 100,000 men and women aged from 50 to 70 years old stratified as 5-years interval. The analysis adopted a social perspective and all costs and outcomes were discounted at 5% for 30 years. The result was presented as the incremental cost per QALY gained. Uncertainty was explored with deterministic and probabilistic sensitivity analysis. RESULTS: The analysis showed that the use of low dose aspirin in addition to routine screening comparing to the screening alone is likely to result in a incremental cost per QALY of around 3,000,000 KRW/QALY to 8,700,000 KRW/QALY for men over than 50 years old and of around 4,700,000 KRW/QALY to 12,000,000 KRW/QALY for women over than 55 years old. The deterministic sensitivity analysis for uncertain parameters demonstrated that this analysis results were robust. Assuming a willingness-to-pay threshold of 15,000,000 KRW per QALY gained, the probabilistic sensitivity analysis suggested that low dose aspirin chemoprevention is more net benefit than screening alone for both men over than 50 years old and women over than 55 years old. However, there was considerable uncertainty in the current evidence available. CONCLUSIONS: Low dose aspirin appears to be cost-effective regardless of the wide distribution of ICER as chemoprevention of colorectal cancer coupled with screening comparing to the screening alone for the men over than 50 years old and women over than 55 years old. Therefore, low dose aspirin can be recommended as chemoprevention therapy in Korean population.