A 71-year-old male was found to have bilateral posteromedial masses on routine roentgenogram during admission for treatment of traffic accident related injuries. These masses were initially considered to be posterior mediastinal tumors, however, CT scan demonstrated a left diaphragmatic defect and the adipose nature of the bilateral masses . MRI also demonstrated a large amount of fat accumulation in the abdomen. CT scan and MRI are therefore very useful for the diagnosis of Bochdalek hernia in adults.