Diaphragmatic rupture occurs in approximately 5% of patients who sustain multiple trauma and post-mortem studies suggest that right-sided rupture is more common than generally realized. Four cases of rupture of the right hemidiaphragm secondary to blunt trauma are presented. The chest radiographs were all similar, demonstrating a right sided fluid collection and right lower lobe consolidation in all patients. No patient had a pneumothorax. CT was useful only in retrospect, demonstrating a posterior eventration of the liver into the thorax in two patients. Ultrasound proved diagnostic in all cases demonstrating either the free edge of the diaphragm as a flap within the pleural fluid or the liver herniating into the thorax. The value of ultrasound as a simple, non-invasive and direct means of imaging the diaphragm is emphasized.