Background: Coaching in nursing is one of the most promising approaches for promoting nurses personal and professional development. Aim: The study aimed to investigate the coaching program effect on nurses' knowledge and practice regarding caring child undergoing cardiac catheterization. Method: Quasi-experimental research design was used in this study. Setting: This study implemented in the pediatric department, Cardiac Intensive Care and cardiac catheterization Units at Beni-Suef University and Health Insurance Hospitals. Sample: A Purposive sample consisted of sixty nurses divided into experimental (30) and control groups (30) from the above-mentioned setting: Tools of data collection: Three tools were used; Tool (I): Structured interviewing questionnaire consisted of two parts: Part (1): Personal characteristics of the nurses. Part (2): Nurses' knowledge questionnaire. Tool (II): Performance checklist and Tool (III): Coaching Practice Rating Scale, used by the nurses as a self-evaluation instrument to reveal on the degree to which their coaching practices. Results: Post the coaching program applied, the total knowledge scores were significantly higher in the experimental group than in the control group (t=3.94, p=.001). As well, the performance scores were significantly higher in the experimental group than in the control group (t=4.26, p < .001) and the coaching practice scores were significantly higher in the experimental group than in the control group (F=5.89, p < .001). Conclusion: The coaching program is a very effective method for improving nurses' knowledge and performance in caring for children undergoing cardiac catheterization, as well as enhancing their coaching practice. Recommendation: Continuous application of the coaching program for nurses caring for children is essential to improving their performance and coaching skills