Congenital cystic adenomatoid malformations (CCAMs) are rarely diagnosed in adulthood. The present case study reports a case of a CCAM presenting as a cerebral air embolus during an international flight. In the present case, supportive therapy resulted in a full recovery. The patient later underwent elective excision of the pulmonary malformation. Since the overall mortality of in-flight cerebral air embolisation is high, patients with such asymptomatic cysts should be considered for elective surgery.