OBJECTIVES: Worker's health is an important index used to evaluate working conditions and to prioritize prevention policies. However, this index has never before been calculated in Korea. The purpose of this study was to calculate the prevalence of health problems caused by work related sickness absences using the second Korean Working Condition Survey (KWCS) conducted in 2010. METHODS: The second KWCS was conducted from June to October 2010 as a household survey for employed workers. The work related sickness absence rate was estimated using gender, age, business size, occupational status, level of education, and level of income. A logistic regression was performed in order to evaluate the relationship of the work related sickness absence with general characteristics and work-related conditions. RESULTS: The rate of work related sickness absence was 1.8(+/-0.2)% for all workers, with 6.0(+/-0.3)% of it being in agriculture, forestry, and fishing, and 2.2(+/-0.5)% in manufacturing. Musculoskeletal disorders (MSD) were the most common work related disorder [1.01(+/-0.12)%], followed by psychiatric disorders [0.18(+/-0.05)%], and respiratory disorders [0.14(+/-0.04)%]. The highest odds ratio (OR) for the work related sickness absence rate was in self-employed workers with employees (OR=2.23, 95%CI=1.05~4.74). CONCLUSIONS: The work related sickness absence rate for all workers, both self-employed and employed, including agriculture, forestry and fishing workers, and wholesale and retail trade workers was 1.8(+/-0.2)%. Because the KWCS was based on a self-reported questionnaire survey, this figure might be overestimated. In addition, it might omit chronic occupational disease and death cases.