Chest physiotherapy is an essential component of the multidisciplinary approach in critical care settings. In this context, a number of devices and manual techniques have been used to remove pulmonary secretions and re-expand collapsed areas. This study was designed to evaluate whether manual rib cage compression improves airway clearance and respiratory mechanics in mechanically ventilated patients. In a randomized crossover trial, 20 mechanically ventilated patients underwent thoracic manual compression and control intervention (normal ventilation) at the same day. The main outcomes were sputum production and the changes in respiratory mechanics.