This study was carried out to assess work ability of manufacturing workers and managerial workers. Subjects were 446 manufacturing workers and 278 managerial workers employed in Gumi industrial complex and the observation period was for 1 month(February to March), 1995. In this study, as a questionnaire for the assessment of work ability, we used the work Ability Index(WAI) which was developed by Institute of Occupational Health in Finland. Major findings obtained from this study were as follows; WAI was poor in lower economic condition, shift work, irregular diet group(p < 0.05). There were no evident trends of WAI in sex, educational level, obesity index, exercise, smoking, and alcohol drinking. In the groups of sensitive to perception of stress, other industrial classification except textile and electronics, the more than 9 hours work, the evident trends of poor WAl were observed(p<0.01). In the groups of 30-39 years old, 40-49 years old, unmarried, high school, shift work, standard body weight, and regular diet, WAl between manufacturing workers and managerial workers was significantly different(p<0.01) and WAI of managerial worker was worse than that of manufacturing worker.