Background: In all healthcare settings across the world, missed nursing care is a problem that regularly leads to serious incidents that reduce the level of care. Aim: The aim of the study was to evaluate nurses' knowledge and practice regarding missed nursing care. Subjects and Methods: Design: A descriptive design Setting: study was used in the intensive care units at Mansoura University Hospital. Subjects: Study subjects included all nurses employed in the selected units at the time of the study, with a total of 98 nurses. Tools of Data Collection: Two tools were used to collect the data of the study; a Missed nursing care Knowledge questionnaire, and an observational checklist for nurses ' skills about missed nursing care. Results: The study revealed that 54% of the nurses in the study sample had low knowledge and 63% of them of the studied nurses had unsatisfactory skills regarding missed nursing care. Conclusion: The nurses in the study setting have low knowledge and unsatisfactory skills regarding missed nursing care. Recommendations: Nursing managers need to develop an educational program regarding missed nursing care for all nursing staff.