Surgical approaches for traumatic diaphragmatic hernia include transabdominal, transthoracic, and thoracoabdominal. Selection of the optimal approach depends on the timing and organ damage, often minimally invasive approaches with laparoscopy or thoracoscopy are performed. A 47‐year‐old man with blunt chest trauma was diagnosed with left traumatic diaphragmatic hernia 1 month after the trauma. The prolapsed omentum was detached from the chest wall and around the hernia orifice and returned to the abdominal cavity by coordinated thoracoscopic and laparoscopic manipulations. The 4 × 2 cm herniation in the diaphragm was sutured closed from the thoracic side while preventing re‐prolapse of the omentum and abdominal organs from the abdominal side. A combined thoracoscopic and laparoscopic approach can be effective in confirming organ damage, repositioning of prolapsed organs, and safe repair of the diaphragm in latent traumatic diaphragmatic hernia.