Cholecystectomy is the surgical removal of the gallbladder and is a standard treatment of symptomatic gallstones and other gallbladder conditions. Nurses have a very important role for patients who underwent cholecystectomy This study aimed to evaluate the effect of an educational program on nurses' performance regarding care for patients undergoing cholecystectomy. A quasiexperimental design was utilized. The study was conducted in three surgical departments at Zagazig University Hospitals, hepatic surgery and endoscopy department, general surgery department and vascular surgery department. The study was conducted on convenience sample of available nurses working in surgical departments and caring for patients undergoing cholecystectomy. Three tools were used; an interviewing questionnaire, an observational checklist and nurses’ attitude questionnaire. More than half (52%) of studied nurses aged less than 30 years old, 92% of the studied nurses were females and married, 40% of the studied nurses had diploma degree and 44% of the studied nurses worked in general surgery department, 52% of studied nurses had less than ten years of experience in surgical departments and 100% of studied nurses didn't receive any training program about cholecystectomy. Total satisfactory nurses’ knowledge and practices regarding patients undergoing cholecystectomy was improved post program compared to preprogram. Total nurses` positive attitude regarding patients undergoing cholecystectomy was improved post program compared to preprogram. There was a statistical significant relation between nurses' attitude and their social status and department. There was a statistical significant relation between satisfactory nurses' knowledge and their practice pre and post program phases. There was a statistical significant relation between nurses' attitude and their knowledge and practice. There was a statistically positive correlation between nurses' knowledge score, and their attitude score, and practice score, nurses' age and years of experience. There was statistically positive correlation between nurses' attitude score, and their practice score. The researcher can concluded that the educational program significantly improved nurses' knowledge and practices, which reflected on improving their positive attitude regarding patients undergoing cholecystectomy. Continuous in-service training programs are recommended to improve and maintain nurses’ performance regarding patients undergoing cholecystectomy.