Bochdalek hernia is a congenital posterior diaphragmatic defect resulting from failure of the retroperitoneal canal membrane to fuse with the dorsal esophageal mesentery and the body wall. A recent computed tomography study indicated that these defects frequently can be identified on routine chest and abdominal images, and classified them as small, medium, and large, the large ones being identifiable on five or more contiguous axial scans consisting of 1-cm-thick sections. Although the overall prevalence of Bochdalek hernias is 6%, and that of bilateral hernias is 0.9%, to date only a few patients with unilateral or bilateral large hernias have been reported. This article describes an adult with asymptomatic, bilateral, large Bochdalek defects containing herniated retroperitoneal fat.