A case of bronchogenic cyst associated with extralobar pulmonary seque
stration is presented in a 10-month-old baby. At thoracotomy, the tumo
r was an extralobar pulmonary sequestration with a central cyst surrou
nded by two pulmonary lobes vascularised by systemic vessels. Resectio
n was easy. The cyst had a respiratory mucosa and was benign. The path
ogenesis of the malformation is discussed.