Cholecystectomy is the surgical removal of the gallbladder. Surgical options include the standard procedure, called laparoscopic cholecystectomy, and an older more invasive procedure, called open cholecystectomy. Approximately 700,000 cholecystectomies are performed annually in the United States. The Aim of the study is to assess nurses' knowledge and practice regarding postoperative open cholecystectomy patients. Descriptive research design was utilized in this study .This study was conducted in the general surgery department at Assiut University Hospital. A convenient sample of 60 nurses was included in this study. Data collected by utilizing the designed interview questionnaire sheet consists of biosocial characteristics of nurses and assessment of nurses' knowledge, observation checklist sheet. The results can be concluded that more than half of nurses (81.7%) had poor level of knowledge regarding nursing care of open cholecystectomy. All nurses (100%) had an inadequate level of practice regarding nursing care for patients post open cholecystectomy. It was found that there was a positive relationship between total knowledge score and total practice score. Conclusion: it can be concluded that, Nurses` knowledge and practice regarding nursing care of patient post cholecystectomy are at a poor and inadequate level and need developing nursing care standards to improve nurses` knowledge and practice.