Background: Healthcare facilities can reduce their environmental impact and occupational hazard by promoting green management. Aim: This study aimed to assess the effect of a green management training program on nursing managers' perception of occupational safety and green management practices. Research design: quasi-experimental research design was used.  Setting: this study carried out at Sohag University Hospital. Sample: involving 42 nursing managers' from inpatient units. Tools: Three tools were used structured interviewing questionnaire for demographic data and concerned nursing managers' knowledge; green management practices questionnaire; and Occupational Safety Scale were used to collect data. Results: Prior to the intervention, 83.3% of nursing managers' had a low level of green management, which improved to a high level for 80.9% of them post-intervention and sustained for 76.2% at the follow-up stage. Similarly, prior to the intervention, 66.7% of nursing managers had low levels of occupational safety, which improved to high levels for 88.1% of them post-intervention but decreased to 85.7% at the follow-up stage. Conclusion: The green management training program significantly improved nursing managers' green management practices and knowledge and led to a sustained improvement in their occupational safety. Recommendations: Continuing to provide green management training programs for nursing managers' to maintain the positive impact on their practices and knowledge, and conducting periodic assessments to monitor progress and identify areas that need improvement.