Purpose: Postoperative nausea and vomiting (PONV) is very common among postoperative orthopedic surgical patients with patient-controlled analgesia (PCA), especially for narcotics. Therefore, the purpose of this study was to investigate the effects of an evidence-based PONV management protocol on nursing and patient outcomes. Methods: A methodological study was conducted to develop PONV protocol and a quasi-experimental study to evaluate the effectiveness of protocol. The preliminary PONV protocol was drawn by conducting a systematic review and by reviewing clinical guidelines and best practice recommendations. Validation of the content was done by expert clinicians, and the clinical applicability was evaluated by staff nurses and patients. The effect was evaluated in clinical outcomes associated with PONV and nursing outcomes. Results: In the experimental group, the occurrence of vomiting (z=2.147) was significantly decreased, the maintenance PCA (X2=4.212) and the satisfaction of patients (z=5.007) were significantly higher. In the outcomes of nurses, the PONV knowledge of nursing care (z=3.791), awareness (z=2.982) and self-efficacy (z=2.745) were higher in the experimental group. The attitude towards evidence-based nursing practice (z=2.446) was significantly positive. Conclusion: The results show that an evidence-based approach to the implementation of PONV care is effective in improving patient clinical outcomes and quality of care.