Background: Workplace bullying is a prevalent problem in today's work places that has adverse effects on both bullying victims and organizations. To investigate the predictors of workplace bullying is an important task to prevent bullying victims of nurses in hospitals. Objective: This study aims to explore the relationships among nurses' attitudes, negative perceptions, and negative acts regarding workplace bullying under the framework of the theory of planned behavior (TPB). Methods: A total of 811 nurses from three hospitals in Taiwan were surveyed. Nurses' responses to the 201 items of 10 scales were calibrated using Rasch analysis and then subjected to path analysis with partial least-squares structural equation modeling (PLS-SEM). Results: The instrumental attitude was significant predictors of nurses' negative perceptions to be bullied in the workplace. Instead, the other TPB components of subjective norm and perceived behavioral control were not effective predictors of nurses' negative acts regarding workplace bullying. Conclusions: The findings provided hospital nurse management with important implications for prevention of bullying, particularly to them who are tasked with providing safer and more productive workplaces to hospital nurses. Awareness of workplace bullying was recommended to other kinds of workplaces for further studies in future.