Background <p>Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in intensive care units (ICUs) and is associated with increased mortality, the use of antimicrobials, prolonged mechanical ventilation, and more expensive healthcare expenses. The purpose of this study was to evaluate the effectiveness of lung ultrasound in the early detection of ventilator-associated pneumonia and predictors of mortality.</p> Methods <p>This prospective observational longitudinal study was carried out on 40 mechanically ventilated patients with suspected VAP, admitted to the ICU of the Chest Department at Tanta University Hospitals. All patients were allocated into two groups based on radiological findings: the ventilator-associated tracheobronchitis (VAT) group (<i>n</i> = 9), which included patients who showed no radiological findings, and the VAP group (<i>n</i> = 31), which included patients who showed radiological findings.</p> Results <p>There was a significant difference between chest ultrasound and CXR at the time of VAP suspicion, in which 67.7% patients showed findings in ultrasound in comparison with 35.5% patients showing findings in CXR (<i>P</i>-value = 0.01). A Pao2/Fio2 ratio of less than 240, bilateral radiological opacity in CXR, and lung ultrasound pleural effusion were all associated with an increased mortality rate in VAP patients, as revealed by the multivariate logistic regression analysis.</p> Conclusions <p>Chest ultrasound is a reliable bedside method for early VAP detection and is found to be better than CXR, especially in respiratory ICU. Sonographic findings of pleural effusion were found to be correlated with higher mortality in VAP patients. Gram-negative organisms (<i>Klebsiella</i>) were the most common isolated organisms in VAP patients in respiratory ICU.</p>