Purpose: This study was conducted to examine the influence of workplace bullying (WPB), bystander types, and psychological safety on the intention of advanced beginner nurses to report medication errors. Methods: A cross-sectional survey conducted from July to November 2024 used a structured questionnaire covering WPB bystander type, psychological safety, and intention to report medication errors. Data were collected from 188 advanced beginner nurses employed at two tertiary hospitals in South Korea. A multiple regression model, controlling for gender and the number of medication errors experienced, was used to assess the effects of WPB, the four bystander types (abdicators, facilitators, active defenders, supportive defenders), and psychological safety. Results: The model explained approximately 19.0% of the variance in the intention of advanced nurses to report medication errors. Supportive defender behavior and psychological safety had significant positive impacts, while workplace bullying had no significant effect. Conclusions: Strategies such as supportive defender behavior should be developed to promote positive bystander behaviors and enhance psychological safety for improved patient safety.

• Bullying, Bystander, Medication Error, Incident Reporting, Psychological Safety