Background: Nasogastric tube feeding is the most frequently used method of enteral feeding among critically ill patients and it is accompanied by some complications that can lead to increased morbidity and mortality. Aim of the study: Was to evaluate the effect of implementing nursing guidelines on nurses' performance regarding complications of nasogastric tube among critically-ill patients.  Design: Quasi- experimental research design was utilized in this study to achieve the aim of this study. Setting: The study was carried out in Intensive Care Unit at Benha University Hospital. Subjects: Convenientsample (60) nurses. Tools of data collection: Two tools were used, I: Self-administered questionnaire to assess nurses' knowledge regarding nasogastric tube and its complications, II: Observational checklist to assess nurses' practice during caring for patients with nasogastric tube and its complications. Results: The study revealed that nurses' knowledge and practice score regarding nasogastric tube pre guidelines implementation was (70% and 53.3%), mean score (14.6833±5.85848 and 131.2833±12.85920)  which improved immediately post guidelines implementation (93.3% and 95%), mean score 36.6833± 2.04601 and 271.5667±8.19749 as (p≤0.001). Conclusion: Providing nursing guidelines has been shown to be effective on nurses' performance regarding complications of nasogastric tube among critically ill patients. Recommendation: In service education and training for nurses regarding prevention and management of nasogastric tube complications among critically ill patients.