We present a 48-year-old man with delayed hepatothorax due to right-sided traumatic diaphragmatic rupture. An initial chest radiograph showed no specific signs except elevation of the right diaphragmatic border. The diagnosis was confirmed by coronal reformatted helical computed tomography (CT) imaging, which revealed intrathoracic displacement of the liver. A follow-up chest radiograph revealed gradual elevation of the right diaphragmatic border, suggesting worsening of the diaphragmatic rupture and progression of hepatothorax, resulting in severe atelectasis of the right lung. Therefore, surgical repair of the diaphragmatic rupture was performed. Impaction of the liver through the diaphragmatic ruptured region was observed. Chest radiographic examination after the operation revealed a more normal position of the right diaphragmatic border and resolution of the right lung atelectasis. The problems associated with the diagnosis and operative treatment of hepatothorax with right-sided traumatic diaphragmatic ruptures are discussed in the light of this case report.