Objectives: This paper aims to investigate the influence on stress hormones of job stress resulting from firefighting duties, as well as the degree of such influence. Methods: KOSS-26 and stress hormones such as norepinephrine (NE), epinephrine (EPI), adrenocorticotrophic hormone (ACTH), and cortisol were analyzed for 191 male firefighters from the western area of Incheon, the Incheon Industrial Complex, and Bucheon, Korea. Job stress and stress hormones were compared between a office working group and field-working group. Results: There was no significant difference in EPI and ACTH between the two groups. Change of stress hormones prior to engaging in typical duties, following typical duties, and immediately after field activities was examined. All the EPI, ACTH, and cortisol showed statistically significant changes with time, but not NE in the blood. In the field-working group, the cortisol levels in the blood of the firefighting and rescue groups showed notable differences depending on the time at which the measurements were taken. Conclusion: The differences in stress hormone levels depending on the type of duties of the firefighters were identified. Thus, interventions proper to job requirements is required in order to ease stress.