The purpose of this study was to assess both direct and indirect relationships between professional commitment, job satisfaction, and work stress in public health nurses (PHNs) in Taiwan. The two major questions addressed were as follows: What were the professional commitment, job satisfaction, and work stress among PHNs? What model accurately portrays the relationships between these three independent variables? Exploration of the causal pathways among these variables revealed a fitness model. A structured, self-administered questionnaire with three scales was distributed to the subjects. A total of 258 subjects completed the questionnaire, yielding a 90% response rate. Results demonstrate a significant, direct, and positive effect of professional commitment on job satisfaction, as well as a significant inverse influence of job satisfaction on work stress. An indirect effect of professional commitment on work stress through job satisfaction was also revealed in the findings. All paths in the model were significant (P < .05). The findings of the study can help show that professional commitment plays an antecedent role to job satisfaction and work stress of nurses. This study suggests that professional commitment is an important factor related to work stress and that health care institutions should be concerned with this issue.