OBJECTIVES: This study was conducted to investigate the job stress factors, psychosocial stress and their associations in workers engaged in the research and development of vehicles, and according to job role. METHODS: We recruited 4,066 subjects from workers at a research and development center of an automobile company. A total of 2,764 workers answered the questionnaire about socio-demographic factors, health behaviors, work-related factors, subjective labor intensity, KOSS, and SF-PWI. The final analysis included 2,282 male manufacturing and research workers. Univariate analyses and multiple logistic analyses were conducted on the complete questionnaire data to compare the job stress factors, psychosocial stress and their associations between research and manufacturing workers. RESULTS: The adjusted Odds ratios comparing the high risk group to the low risk group regarding PWI group were 2.23(95%CI=1.63-3.04) in "Lack of rewards", 1.64(95%CI=1.20-2.24) in "Interpersonal conflict", 1.59(95%CI=1.15- 2.20) in "Organizational injustice", 1.58(95%CI=1.17-2.14) in "Occupational climate" and 1.43(95%CI=1.05-1.94) in "Job insecurity" among research workers, and 2.46(95%CI=1.59 -3.80) in "Lack of rewards" and 1.94(95%CI=1.17-3.22) in "Organizational injustice" among manufacturing workers. CONCLUSIONS: There are differences in job stress factors between research and manufacturing workers. Further studies and discussions based on quantitative methodology for seeking more fundamental causes of these differences are required to establish job stress intervention plans and policies.