Mechanical ventilation is a backbone and the major supportive modalities in intensive care unitsrneven though it has its own side effects and complications. Nursing care plays a crucial role in thernprevention and early recognition of this complication. Knowledge of nurses about mechanicalrnventilators and good practice of nursing care for the ventilated patient plays a crucial role inrnimproving the effectiveness of mechanical ventilation, preventing harm, and optimizing thernpatient outcome. rnObjective: The objective of this study was to assess the knowledge regarding MV and thernpractice of ventilatory care among nurses working in ICU at selected governmental Hospitals inrnAddis Ababa; Ethiopia, 2021rnMethod: -Descriptive cross-sectional study design was conducted to determine the knowledgernand practice of nurses working in intensive care units towards mechanical ventilators at selectedrngovernmental hospitals. All nurses working in the intensive care unit of selected governmentalrnhospitals were included in the study. Data was collected from March 1 to 30, 2021 withrnstructured and pretested self-administered questionnaires. The collected data was entered intornEpi-data version 4.6 and exported to Statistical Package for the Social Sciences (SPSS) versionrn26 Software for further analysis. The results were expressed in tables, charts diagrams, andrngraphs. rnResults: A total of 146 nurses participated in the study, the majority (51.4%), were males andrn(58.9%) within the age group of (20-29) with a mean age of (29.84Â±4.95). About, 71.4% had a rnBSc holder in nursing, and (57.5%) had less than 5 years of working experience in ICU andrn(57.5%) of them had training related to MV. This study showed that (51.4%) and (58.9%) ofrnnurses have poor had poor knowledge and practice regarding MV and ventilatory carernrespectively. Level of education was significantly associated with the knowledge level ofrnparticipants with (P-