Background: The use of oral hygiene approaches is vital for maintaining the health and comfort of patients. This is especially true for those in intensive care who are intubated and on mechanical ventilation because proper oral hygiene practices greatly reduce the possibility of complications and shorten hospital stays for such patients. Aim: The aim of this study is to evaluate the effect of oral care protocol on oral health status among mechanically ventilated patients. Research Design: A quasi-experimental study with one group pre-test and post-test design was utilized for the current study. Setting: The study was carried out in the intensive care unit at Cairo university hospital. Sample: A purposive sample of (30) male and female patients admitted to the ICU. Tools of data collection: Two tools were utilized to collect data pertinent to the current study: tool (1) patient's demographic and medical data sheet, tool (2) Beck oral assessment score (BOAS) modified. Results: There is a significant decrease in total mean oral health score post intervention in the 3 days which indicates that there is an improvement in the oral status after oral care, there is a significant decrease in mean oral health score post intervention for all BOAS subscales, the teeth and saliva were the most subscales improved after the intervention. Conclusion: The oral health status of mechanically ventilated patients improved after the intervention of oral care. Recommendations: Applying oral care for mechanically ventilated patients, the oral health condition of intubated patients should be frequently assessed in the ICU utilizing oral assessment tools as a basis for intervention.