Background: Ventilator-associated pneumonia (VAP) is pneumonia occurring 48-72 hours or later following endotracheal intubation. It is characterized by the presence of an infiltrate, whether new or progressive, signs of systemic infection (fever, leukocytosis), change in sputum, and detection of an agent. VAP is mainly acquired through either major or micro aspiration of oropharyngeal organisms into the distal bronchi, directly or via reflux from the stomach into the oropharynx. Objectives: This study aimed to measure VAP rates, identify the causative organisms and demonstrate whether an association exists between bacterial pathogens causing late onset VAP and bacteria isolated from gastric aspirate in mechanically ventilated patients admitted to the Respiratory Intensive Care Unit of Ain Shams University Hospital, Cairo, Egypt. Methodology: This cross-sectional study was carried out over a period of 6 months from September 2015 to February 2016 and included 100 mechanically ventilated patients. Gastric aspirate from naso-gastric lavage and bronchoalveolar lavage (BAL) were obtained after establishment of diagnosis of late onset ventilator associated pneumonia. Results: Candida species and P. aeruginosa were the most predominant microorganisms found in BAL, each being isolated in 23.1% of cases. Klebsiella pneumoniae was the second commonest isolated organism from BAL and the most common in Ryle tube. Conclusion: Agreement between BAL and Ryle organisms occurred in 8 of 100 mechanically ventilated patients only. We concluded that a clear association can not be reached by the limited number of specimens. We recommend tight adherence to infection control preventive measures for mechanically ventilated patients in ICU to reduce the VAP rates.