Background: Colostomy is a surgical procedure that involves creating an opening in the abdominal wall to divert the flow of stool from the colon to a stoma. This procedure can have a profound impact on the lives of pediatric patients and their families, requiring specialized care and support. The nurse can play a clinically relevant role in the care of children undergoing colostomy surgery pre and post-operative colostomy. This study aimed to investigate the effect of simulation-based intervention on nurses' performance and satisfaction regarding colostomy care at the pediatric surgical unit. Method: a quasi-experimental design was utilized to fulfill the purpose of this study. Setting: The study was conducted in the Pediatric Surgical Unit affiliated to Sohag University Hospital. Subjects: all nurses (50) caring for children with colostomy who are working in the Pediatric Surgical Unit were included. Tools for data collection: (1) colostomy questionnaire sheet (2) observational checklist, and (3) nurses satisfaction scale was used to collect data. Results:  There was a highly statistically significant difference between the studied nurses' knowledge, practice, and satisfaction.    The study result revealed that more than half of the studied nurses had a poor level of knowledge, and more than half of them had an unsatisfactory level of practice about colostomy before the implementation of the simulation-based intervention. The vast majority of the studied nurses had a good level of knowledge and most of them had a satisfactory level of practice after implementing simulation-based intervention. There was a highly statistically significant difference and improvement in nurses' performance after simulation-based intervention than pre-intervention. Conclusion: The present study concluded that simulation-based intervention had a positive effect on improving nurses' performance and satisfaction regarding colostomy. Recommendations: The study recommended that simulation-based intervention should be integrated as an effective method in nurses' training about colostomy.