OBJECTIVES: This study was performed to analyze the factors that affected the decision making process in approving workers' compensation claims for cerebrovascular and cardiovascular diseases cases that occurred just before refoming approval standards of Industrial Accident Compensation Insurance Act on 1 July 2008 and to provide fundamental information in preparing better standards. METHODS: We examined 283 claims cases involving cerebrovascular and cardiovascular diseases that occurred between 1 January, 2006 and 31 December, 2007 and collected data based on the worker's compensation records from 3 Seoul Regional Centers of the Workers' Compensation & Welfare Service. We analyzed the approval rates and odds ratios according to the general characteristics, injury information, past medical histories, and work related information using chi-square or univariate logistic regression. In addition, we identified the factors affecting the approval using multivariate logistic regression. RESULTS: Overall, 101 of the 283 cases were approved and approval rate was 35.7%. Approval rates differed significantly according to type of disease, survival, accident site, accident time, the presence of associated disease and overwork (p-value <0.05). In the multivariate logistic regression analysis with adjusted for age and sex, approval rate of death cases with associated disease was lower than cases without associated disease (OR 0.22, 95% CI 0.12~0.42). Approval rate of cases occurred in worksite was higher than others (OR 4.81, 95% CI 2.22~10.40). Cases of accepted overwork had a higher approval rate significantly than cases of not accepted (OR 28.53, 95% CI 9.74~83.52). CONCLUSION: Factors in approving cases of cerebrovascular and cardiovascular disease as cases involving occupational disease included conditions of overwork, high rate of accidents in the workplace and the presence of associated disease. It is necessary to investigate further behaviors of work and chronic work-related stress.