Objectives: The aims of this study were to investigate the factors affecting the fatigue and stress in male manufacturing workers. Methods: A questionnaire investigating general characteristics, lifestyle factors, job characteristics, fatigue and stress was distributed to 896 subjects. From 851 respondents, 11 responses with insufficient data were excluded. The data were analyzed to investigate the factors affecting personal fatigue and stress. Results: Among the general characteristics, both fatigue and stress in the older group were significantly lower than in the younger group (p<0.05). Fatigue in the group with higher education was significantly higher than in the group with only high school education (p<0.05). The group who lived alone had significantly more stress (p<0.05). Among lifestyle factors, people who exercised regularly had significantly lower fatigue and stress than those who did not (p<0.05). Fatigue was negatively correlated with decision latitude, supervisor support, and coworker support. Stress was positively correlated with job demand and negatively correlated with decision latitude, supervisor support, and coworker support. Fatigue and stress were positively correlated with each other. Multiple linear regression analysis showed that among job characteristic factors, coworker support affected fatigue while job demand and supervisor support affected stress. Conclusions: Fatigue and stress were positively correlated, but the job characteristics that affected each were different. This suggests that for effective management of fatigue and stress, the details of job characteristics need to be considered individually for the intervention and prevention of fatigue and stress.