The improper fusion of the posterolateral foramina of the diaphragm was first described by Bochdalek in 1848. The true incidence of this congenital anomaly ranges from 1/7,000 to 6%. Although it is a well-known neonatal disease, it can also be diagnosed incidentally in adult patients. Until now, a total of around 100 cases of occult asymptomatic Bochdalek's hernia have been reported. The symptomatic cases are encountered more rarely. Colon necrosis among the symptomatic cases was reported in some cases. We herein report a case of a 21-year-old man with a left-sided Bochdalek's hernia which led to total necrosis of the transverse colon. Following resection and colocolonic anastomosis, the defect on the diaphragm was repaired. After an uneventful recovery period, he was discharged from the hospital on the 10th postoperative day. Being aware of this rarely encountered disease and of the factors for early diagnosis is of utmost importance to decrease mortality and morbidity.