Ventilator-associated pneumonia results from bacterial colonization of the aerodigestive tract or aspiration of contaminated secretions into the lower airways. As a consequence of infection of the lung parenchyma and alveolitis, accumulation of inflammatory exudates and infiltration of airway mucosa can lead to unfavorable respiratory mechanics in ventilator-associated pneumonia. Tracheal suction is often employed by Physiotherapists in the management of mechanically ventilated patients with ventilator-associated pneumonia but this technique has the potential to increase respiratory resistance. Manual hyperinflation is used by physiotherapists to improve lung volume and mobilise secretions and has been shown to increase lung compliance. Aims and Objectives: To demonstrate an additional mechanical benefit to the respiratory system when manual hyperinflation and suction techniques are combined, by comparing the application of manual hyperinflation and suction with suction alone on static lung compliance (CL) and Inspiratory resistance (RAW) in mechanically ventilated patients with ventilator-associated pneumonia. Study Design: Thirty patients with ventilator-associated pneumonia were recruited and a Crossover study with Randomisation of sequences was done. Manual hyperinflation followed by suction (manual hyperinflation plus suction) and suction alone were applied consecutively, in random order, on two occasions, four hours apart. Respiratory variables, CL and RAW, were measured five times and the averaged value documented. Data were recorded before, immediately after, and 30 minutes after each intervention protocol. Results: CL increased by 4% and RAW decreased by 10%, up to 30 minutes after Manual hyperinflation plus suction, but not after suction alone. Conclusion: This study suggests that manual hyperinflation in conjunction with suction induces beneficial changes in respiratory mechanics in mechanically ventilated patients with ventilator-associated pneumonia.