Abstract Background: Gastrointestinal surgery is a specific surgical area where different patients are involved and ensuring a positive postoperative outcome after major surgery is still a difficult goal to achieve so, the process of nursing care in gastrointestinal surgery is specific because of the limited time of patient hospitalization, so nurses' play a core role in the management of patients undergoing gastrointestinal surgery. Aim of the study:  To assess nurses' performance and postoperative outcome among patients undergoing gastrointestinal surgery. Subjects and Methods; Research design: A descriptive   research design was carried out in this study. Setting: The present study was conducted in gastrointestinal surgical unit, surgical operation and post anesthestic care units at Zagazig university hospitals. Subjects: A convenience sample of all available nurses (30) working in the mentioned setting and a purposive sample of 70 patients who fulfilling the inclusion criteria. Tool of data collection: Three tools were used for collecting data. Tool I: A self-administrated questionnaire about studied nurses. Tool II: An observational checklist questionnaire for perioperative nursing care. Tool III: Interview assessment questionnaire for patients. Results: Majority of studied nurses (80%) had unsatisfactory total knowledge , nearly three quarter (73.3%) had unsatisfactory total practice regarding care of patient undergoing gastrointestinal surgery and more than half had moderate postoperative surgical outcome. Conclusion: The majority of nurses' had unsatisfactory total  knowledge and practice regarding care of patients undergoing gastrointestinal surgery, there were statistical significant positive correlation between total nurses' knowledge and total nurses' practice and there were no statistical significance correlation between total patients' postoperative outcome and total nurses' knowledge and practice Recommendation: Training programs are recommended to improve nurses' knowledge and practice regarding care of patients undergoing gastrointestinal surgery. Apply instructional sessions for patients undergoing surgery in the preoperative phase to raise their awareness regarding postoperative quality of recovery and postoperative problems. Study should be replicated on large sample and in different hospital setting in order to generalize the result.