Diaphragmatic paresis following trauma to the phrenic nerves is a rare complication after neck surgery. The resulting elevation of the ipsilateral hemi-diaphragm is diagnosed on post-operative chest radiography and may be confirmed by ultrasound or fluoroscopy. When unilateral, this may lead to respiratory, cardiac or gastrointestinal symptoms and atelectasis and pulmonary infiltrates on radiography. If nerve damage is bilateral a period of ventilation may be required.