Communicating bronchopulmonary foregut malformations (CBPFMs) are characterized by a fistula between an isolated portion of respiratory tissue (ie, a lung, a lung lobe, or a segment) and esophagus or stomach. We combine our 30-year (1959 to 1989) experience of 6 cases with 51 reported patients to propose a CBPFM classification supported by a proposed embryogenesis theory. Group I (16%): anomaly is associated with esophageal atresia and tracheoesophageal fistula. Group II (33%): one lung originates from the lower esophagus. Group III (46%): an isolated anatomic lung lobe or segment communicates with the esophagus or stomach. Group IV (5%): A portion of the normal bronchial system communicates with the esophagus. The portion of the lung served by the communicating bronchus receives systemic blood supply. The right and left lung sacs curve dorsally to embrace the lower esophagus during normal lung development. At this stage a part of the lung bud joins the esophagus. This segment then breaks away from the main pulmonary anlage to form a CBPFM. CBPFMs should be considered in the workup of infants with respiratory distress and/or recurrent pneumonias. Patients with suspected pulmonary sequestration should undergo contrast studies to exclude a gastrointestinal communication.