Total parenteral nutrition for hospitalized critically ill patients is essential for improving outcomes, insufficient nutritional support lead to occurrences of complications, increased morbidity and mortality rates, increased length of hospital stay. Critical care nurses are the cornerstone in preventing theses complications. Aim: To investigate the effect of implementing total parenteral nutrition nursing guidelines on adult critically ill patients’ outcomes. Design: Non randomized prospective research design was used to utilize this study Subjects: convenience samples of 60 patients were assigned equally to study and control group at intensive care units at Assiut University hospitals. The control group received routine hospital care during TPN administration while, the study group received the developed guidelines for TPN during a period from January 2018 to December 2018. Methods Each patient in both groups were assessed by taking history, clinical examination, nutritional assessment laboratory investigation. Patients in study groups were received care according to developed total parenteral nutrition guidelines to determine outcome and complications in both groups. Results Finding of the present study revealed that significant improvement in study group with values of less than p=001 compared to control group Conclusion : implementing of total parenteral nutrition guidelines improve the outcomes and reduce the occurrence of complications among critically ill patients. Keywords : total parenteral nutrition, nursing guidelines, critically ill patient, outcomes DOI : 10.7176/JHMN/61-04 Publication date : April 30 th 2019