Minimally invasive surgery (MIS) in congenital diaphragmatic hernia (CDH) repair has recently been gaining popularity and is the first choice in most departments. Loss of space in an undeveloped abdomen may cause serious problems such as difficult visceral reduction and need for conversion or postoperative complications such as abdominal compartment syndrome. A 4-month-old boy with delayed diagnosis of CDH underwent MIS repair via thoracoscopy, but the abdominal space was not large enough to accept the herniated viscera so a wide transverse fasciotomy was performed via laparoscopy and an iatrogenic ventral hernia induced. The abdomen was distended by pneumoperitoneum, which was retained for 2 days. Finally thoracoscopic CDH repair was completed successfully and the diaphragmatic defect reconstructed by prosthetic patch. Laparoscopic transverse abdominal fasciotomy is suggested as the first step in MIS repair of CDH in an undeveloped abdomen.