OBJECTIVES: This study was conducted to analyze the factors that affected the decision of claims for cerebrovascular disorders and cardiovascular diseases in chronically overworked workers, that submitted their claims after the reformation of approval standards in the Industrial Accident Compensation Insurance Act on 1 July 2008. METHODS: Of 2909 cases, who claimed between January 1. and December 31. 2009, 1046 cases were selected based on their worker's compensation record and investigated following 6 provincial committees for work-related diseases. The approval rate and odds ratio were analyzed with respect to the general characteristics, past medical history and work-related information using a logistical regression and Student t-test. RESULTS: Of the 1046 selected cases, the approval rate was 18.5%(194 cases). In the multivariate logistical regression analysis, the factors for approving cerebrovascular disorders and cardiovascular diseases as work-related diseases were found to be the average working time over the last 1 week, occupational category, gender, age, death or survival, the presence of an associated disease, claimed province, and smoking. CONCLUSION: Factors for approving claims of cerebrovascular disorders and cardiovascular diseases as work-related diseases were the average working time over last 1 week, gender, age, death or survival, claimed disease, presence of associated disease, claimed province, smoking.