Background: The quality of care provided to children undergoing orthopedic surgery is directly impacted by nurses' competency; therefore, competency-based training programs could be modified to help with transitions and ensure better outcomes. The study aim was to evaluate the effect of training program on nurses' competency level regarding care of children undergoing orthopedic surgery. Study design A quasi- experimental with pre and post intervention. Sample: A convenient sample of all available nurses (n=40) and purposive sample of children (n=40) undergoing orthopedic surgery in Pediatric Surgical Department at Benha Specialized Pediatric Hospital. Tool (I): A structured interviewing questionnaire sheet: It included Part1: Personal characteristics of studied nurses, Part2: Personal characteristics of children, Part3: Nurses' knowledge regarding care of children undergoing orthopedic surgery. Tool (II): Observational checklist regarding nursing care of children undergoing orthopedic surgery. Tool (III): Nurses' Competence Scale. Tool (IV): Nurses' attitude regarding competency-based training. Results: regarding nurses' care of children undergoing orthopedic surgery at post training program phase the study result showed that, most of the studied nurses had satisfactory knowledge, (87.5%) of them had competent practice and a positive attitude. In addition to, (92.5%) of them had competent level of total competency. Conclusion: The majority of the studied nurses had satisfactory knowledge, competent practice, positive attitude, and competent level of competency about care of children undergoing orthopedic surgery at post training program application. Recommendations: Implementing competency-based training program in various settings to enhancing the nursing staff's level of expertise in providing care for children undergoing orthopedic surgery.