摘要Objective: To test a causal model of job stress among nurse-midwives working in labor and delivery units in Thailand.Methods: Random and convenience sampling was used to recruit 282 nurse-midwives with at least 6 months of work experience from 16 regional tertiary hospitals in Thailand. Data were collected from May to December 2020. Research instruments with good internal consistency reliability ranged from 0.83 to 0.91 including the Job Stress Scale and the Thai version of the Job Content Questionnaire (TJCQ). Descriptive statistics and a structural equation model were used for data analysis. Results: Job demands were the strongest predictor of job stress. At the theoretical level, high job control plays a crucial role in directly reducing job stress. However, the present research provides contrary evidence to the theoretical predictions. When nurse-midwives perceive high job control, they perceive pressure to meet the expectations of their supervisors and colleagues. Therefore, high job control can contribute to job stress. Likewise, job support had an indirect effect on job stress among nurse-midwives through job control. The modified model fitted the empirical data (χ2 = 57.76, df = 22, CMIN/df = 2.62, goodness of fit (GFI) =0.96, adjusted goodness of fit (AGFI) =0.91, comparative fit index (CFI) = 0.95, and root mean square error of approximation (RMSEA) = 0.07). The effects of job demands, job control, and job support on job stress among Thai nurse-midwives can explain 67％ of the model's total variance for job stress. Conclusions: Nurse-midwives who encounter high job demands and less control over their work control suffer from job stress. Job support does not directly affect nurse-midwives' job stress but influences it through perceived job control. Strategies to decrease job stress among Thai nurse-midwives should focus on how to balance job demands, and enhance job control, and job support.