We encountered two cases of systemic arterial supply to the basal segments of bilateral lung with elevated serum CEA levels. The patients were a 36-year-old man and a 30-year-old man with the abnormal chest shadows, discovered during physical checkups. A chest computed tomogram (CT) of the 36-year-old patient showed reticulonodular shadows in the bilateral lower lobe with anomalous vessels arising from the descending aorta and running into the lower lobe on each side, and his abdominal CT revealed a duplicated vena cava inferior. His aortogram confirmed an anomalous systemic arterial supply to the basal segments of bilateral lungs. The chest CT of the 30-year-old patient revealed a cystic lesion in the right lower lobe and no abnormality in the left lung field. His aortograms showed aberrant systemic arterial supplies to the bilateral lower lobe. Because the cystic lesion had increased in size, it was resected and an anomalous systemic artery was seen. Intralobar sequestration in the right lung and anomalous systemic arterial supply in the left lung was diagnosed. Serum CEA was high at the initial visit in each patient but it decreased spontaneously in the first patient, and after the resection of the cystic lesion in the second patient. We report two cases of anomalous systemic arterial supply to the basal segments of bilateral lung, which is extremely rare. Our literature search revealed that only 13 cases have been reported to date.