Background: Nurses play a crucial role at neonatal intensive care, as they are responsible for administering parenteral nutrition to critically ill neonates. Aim of the study was to assess quality of nurses' performance regarding parenteral nutrition at neonatal intensive care units. Settings: The study was conducted at neonatal. Intensive care units at Benha city in Benha University Hospital, Teaching Hospital and Specialized Pediatric Hospital. Design: A descriptive research design was utilized in the current study. Sample: A convenient sample of 70 nurses was participated in the current study. The tools of data collection were; a structured interviewing questionnaire and an observational checklist. Results: The present study revealed that more than three quarters of studied nurses had unsatisfactory level of total knowledge scores and more than two thirds of the studied nurses had incompetent in their total performance scores also, there was a statically significant relation between of the studied nurses' total knowledge scores and their personal data, there was a statically significant relation between of the studied nurses' total performance scores and their personal data. Conclusion: The present study revealed that there was statically significant relation between of the studied nurses' total knowledge and their personal data; there was statically significant relation between of the studied nurses' total performance scores and their personal data. Recommendation Developing training: programs recommended for the nurses working at regarding parenteral nutrition are neonatal intensive care units to improve their knowledge and performance.