Background: Gastric intubation is a common procedure that gives access to the stomach through the nasal entry for diagnostic and therapeutic purposes. Aim of the study: to assess nurses' performance in nasogastric tube use among patients in critical care units.Research design:  an exploratory descriptive research design was used to carry out this study. Setting: The study was conducted in intensive care units at Ain-Shams University medicine hospital. Subjects: A convenience sample of (80) staff nurses. Data collection tools: data were collected by Structured Self-administered Interview questionnaire, Observational Checklist for nurses' practice, and Nurses' Attitude Likert scale. Results: Three-quarters of studied nurses had an unsatisfactory level of knowledge and one-quarter of them had a satisfactory level of knowledge regarding feeding and administration of medications via nasogastric tube. While less than three-quarters had an unsatisfactory practice level and less than one-third of them had a satisfactory practice level regarding feeding and administration of medications via nasogastric and nursing care during nasogastric tube complications tube. Also, respectively two-thirds of nurses had negative attitudes and more than one-third had positive attitudes regarding feeding and administration of medications via nasogastric tube.  Conclusion: there was a highly significant positive correlation between total level of knowledge, total practice, and total attitude among staff nurses regarding nasogastric tube use among patients in critical care units. Recommendations: Ongoing monitoring of staff nurses' practice by head and charge nurses when caring for patients with nasogastric tubes and provision of guidance to correct poor practices. Further research is replication of the study on a larger sample selected from different geographical areas of Egypt is recommended to generalize the study.