A 27-year-old car crash male victim suffered from short of breath and was hospitalized for observation. On the first day of the traffic accident, chest radiograph showed the blurred right diaphragm (Figure 1A), and axial CT showed a suspected collar sign (Figure 1B). CT scan was performed on a multi-slice CT (Philips Brainliance 16, Philips Medical System, The Netherlands). Three days later, chest radiograph was obtained again due to continuous thoracic pain and short of breath. The chest radiograph revealed right diaphragm elevation and lost of right costo-diaphragm angle (Figure 1C), which was interpreted as a result of pleural effusion and pulmonary atelectasis. Repeated CT scan was carried out. Axial CT images showed the right lobe of liver was dependant against right posterior ribs (dependent viscera sign), waist-like stricture of liver edge (collar sign), and diaphragm thickening (Figure 1D,1E). Diaphragmatic hernia was suspected and multi-planar reformation (MPR) was performed. On MPR images, diaphragmatic discontinuity, portions of liver and colon were demonstrated in the chest cavity (Figure 1F). A definitive diagnosis of right-sided diaphragmatic hernia was established and the patient underwent thoracoscopy assisted diaphragm repair. During the surgery, a central large irregular tear of diaphragm were noted (Figure 1G). A large portion of liver and a segment of colon rose into the thoracic cage through the diaphragmatic tear. After all the abdominal contents were moved back into the abdominal cavity, the tear was sewed (Figure 1H). The patient recovered well.