AIM: To examine occupational stress levels and associated factors among pregnant nurses through a comparison with pregnant non-nurses. METHODS: This cross-sectional study included 1060 working pregnant women. Participants completed questionnaires including the Brief Job Stress Questionnaire, work conditions, obstetric conditions, Sense of Coherence Scale, and self-management behaviors questionnaire. The participants were categorized into four groups: nurses, other healthcare workers, physical workers, and desk workers. Comparisons were made between the four groups and by gestational ages using Dunnett's test and chi-squared test, and associated factors were examined using ordinal logistic regression analysis. RESULTS: Analysis of 847 valid responses showed that the nurse group had a higher occupational stress, higher job demand, and lower job control at any gestational age than the other profession groups. Nurses' occupational stress was associated with factors such as frequent overtime work, fewer break times, lower manager support, and lower prioritizing the fetus. Particularly, fewer break times and lower prioritizing the fetus were nurse-specific associated factors. CONCLUSIONS: The study showed that pregnant nurses are exposed to higher occupational stress throughout the entire pregnancy than other occupations. The stress was related to modifiable factors such as fewer break times and lower prioritizing the fetus. To manage occupational stress, pregnant nurses should avoid overtime, take breaks, and prioritize the fetus in the workplace. Hospital administrators would need to provide work coordination support and consider certain regulations regarding hazardous work restrictions for pregnant nurses. Future cohort studies are required to better understand occupational stress among pregnant nurses.