Background: Percutaneous endoscopic gastrostomy (PEG) is a medical procedure using endoscopic guidance to insert a tube into the patients stomach through the abdominal wall which using as a way to introduce enteral feeding when the oral pathway is not patent. Aim: This study aimed to assess nurses' performance regarding care of patients post percutaneous endoscopic gastrostomies in critical care unit. Design: A descriptive explorative design was utilized for conduction of this study. Setting: the study was carried out in critical care unit of Ain Shams University Hospital. Study subject: A convenience subject of all available nurse's (N=30). Tools: I - Self – administration questionnaire form which composed of nurses demographic characteristics' and nurses' knowledge questionnaire regarding care of patients post percutaneous endoscopic gastrostomies in critical care unit, II nurses' practice observational checklist to assess nurses' performance regarding care of patients post percutaneous endoscopic gastrostomies in critical care unit, Results: This results revealed that, 57% of the studied nurse's had unsatisfactory level of total knowledge about care of patients post PEG in critical care unit and 67% of them had unsatisfactory level of the total practices regarding care of patients post PEG in critical care unit, Conclusion: About more than half of studied nurse's had unsatisfactory level of knowledge and practices regarding care of patients post percutaneous endoscopic gastrostomies in critical care unit. Recommendations: Continuous evaluation of nurses' knowledge and practice is essential to identify their needs in ICU about care of patients post PEG to design nurses' educational program to improve their performance about care of patients post PEG placement.