Objectives: This study was conducted to examine the association between health condition and leaving the labor market among middle-aged and older adults in South Korea. Methods: Data was obtained from individuals aged 45 years and older participating in the 2006 and 2008 Korean Longitudinal Study of Ageing. We used various health measures including chronic diseases, comorbidities, traffic accident injuries, disabilit of instrumental activities of daily living, depressive symptoms, and self-rated health. The odds ratios of job loss, and retirement, versus employment were calculated using multinomial logistic regression by each health measure. Results: In our cross-sectional and longitudinal analysis, health problems related to physical disabilities had the greatest effect on leaving the worksite. A shift in health condition from good to poor in a short period was a predictor of increased risk of unemployment but a persistent pattern of health problems was not associated with unemployment. Women with health problems showed a high probability of retirement, whereas among men, health problems instantly the possibility of both job loss and retirement. Conclusions: Health problems of middle aged and older workers were crucial risk factors for retirement and involuntarily job loss. Especially functional defect and recent health problems strongly and instanty affected employment status.