A bronchogenic cyst was found in the abdomen, in the retroperitoneum adjacent to the superior pancreatic body. The cyst was unilocular and contained about 100 ml pale yellow mucinous fluid. Microscopic examination revealed a pseudostratified columnar ciliated or cuboidal epithelium, seromucous glands, smooth muscle and cartilage, the distinctive features of bronchogenic cysts. This aberrant location of the cyst is explicable if abnormal buds of the tracheobronchial tree are pinched off and migrate into the abdomen in an early embryonic stage before the canal linking the abdominal with the thoracic cavity is closed by fusion of the future components of the diaphragm.