A 3-yr-old boy presented with respiratory distress of 2 days duration. There was a history of blunt trauma to the lower chest having occurred 5 days earlier. Although missed initially, serial chest X-rays and a computed tomographic (CT) scan revealed an isolated traumatic right-sided diaphragmatic hernia without any injury to the viscera or the ribcage. Laparotomy with reduction of the herniated right lobe of the liver and the transverse colon was performed. Recovery was uneventful. The presentation, diagnosis and management of this relatively uncommon injury is discussed. The need for a high index of suspicion and critical evaluation of appropriate investigations to prevent diagnostic delay and optimize management in patients with traumatic diaphragmatic injury is emphasized.