Background <p>Establishing a Just Culture in healthcare is essential to improving patient safety, encouraging open communication, and reducing fear-based silence among staff. Nurse leaders play a critical role in modeling and promoting Just Culture principles. However, the impact of targeted Just Culture programs for head nurses on staff behavior remains underexplored.</p> Aim <p>This study aimed to assess the effect of implementing a Just Culture program for head nurses on silent behavior and error reporting among staff nurses at Ain Shams Specialized Hospital, Egypt.</p> Methods <p>A quasi-experimental, one-group pretest–posttest design was conducted at Ain Shams Specialized Hospital. The study sample included 70 head nurses and 400 staff nurses. Data were collected using five tools: (1) a demographic and work-related data sheet; (2) Head Nurses’ Just Culture Knowledge Assessment; (3) Just Culture Assessment Tool (JCAT); (4) the Silent Behavior Scale for Nurses (SBSN); and (5) the Staff Nurses’ Error Reporting Questionnaire. Statistical analysis was conducted using SPSS version 20. Paired sample t-tests were used to compare pre- and post-program scores. The Chi-square test was applied to assess changes in categorical variables (e.g. knowledge levels). A p-value ≤ 0.05 was considered statistically significant. Cohen’s d was used to determine effect sizes.</p> Results <p>Following the educational intervention, head nurses demonstrated statistically significant improvements in their knowledge and perceptions of Just Culture across all measured domains (p &lt; 0.001). The overall Just Culture knowledge score increased markedly from a mean of 61.0 ± 9.5 pre-program to 88.5 ± 6.2 post-program, with large effect sizes (Cohen’s d 1.3) indicating a substantial impact. Similarly, perception showed a significant improvement following the intervention, increasing from a pre-program mean of 72.7 ± 10.2 to a post-program mean of 111.2 ± 8.6 (t = 13.95, p &lt; 0.001). Among staff nurses, there was a significant reduction in silence behaviors, as evidenced by decreased scores on the Silent Behavior Scale for Nurses (SBSN) (p &lt; 0.001), alongside notable increases in frequency and accuracy of error reporting post-intervention (p &lt; 0.001). Effect sizes for all staff nurse outcomes were large (Cohen’s d 1.5), reflecting meaningful improvements in communication and error reporting culture.</p> Conclusion <p>Implementing a Just Culture educational program for head nurses led to significant improvements in managerial understanding and support for safety culture. These changes positively influenced staff nurses’ communication behaviors and error reporting practices. Findings suggest that leadership-based Just Culture programs can be an effective strategy for enhancing patient safety outcomes in hospital settings.</p> Clinical trial registration <p>Not applicable.</p>