Diaphragmatic ruptures after blunt trauma are rare life-threatening conditions. Most of them occur on the left-sided hemidiaphragm with herniation or associated organ injuries after a motor vehicle accident. We present an unusual case of blunt diaphragmatic rupture resulting in a delayed hemothorax. A 62-year-old man presented with acute dyspnea that initiated while straining to pass stool. He had a bruise on the lower back region of his right thorax after a slip-and-fall accident 7 days previously. Chest computed tomographic scans revealed a right-sided hemothorax without any evidence of herniation or associated organ injuries. Emergency surgery was performed through a video-assisted minithoracotomy. During surgery, we identified a diaphragmatic laceration with a severed blood vessel originating from the right superior phrenic artery. The lesion was repaired with interrupted horizontal mattress sutures. The total amount of bleeding was approximately 2000 mL. The patient had an uneventful recovery with no further bleeding episodes.