To assess fetal vs. neonatal diagnoses, pregnancy outcomes and need for surgery in babies prenatally diagnosed with congenital pulmonary airway malformation (CPAM) or bronchopulmonary sequestration (BPS). Retrospective single-centre cohort study of fetuses with a prenatal diagnosis of CPAM or BPS between 2006 and 2014. Data collected included serial antenatal ultrasound information and neonatal/infant diagnoses and outcomes. Initial ultrasound diagnosis (n=63) was CPAM in 51 and BPS in 12: nineteen (30%) fetuses had mediastinal shift and 2 (3%) had hydrops. All neonates with known birth outcome (n=56) were liveborn. Final diagnosis in 52 infants (83%) with neonatal imaging and/or histopathology confirmed CPAM in 17/44 (39%) and BPS in 6/9 (67%). Of 34 prenatally suspected but unconfirmed CPAM lesions: 10 hadno lesion on neonatal imaging, one no neonatal imaging performed, five confirmed BPS, 11 other lung/thoracic lesions, seven were lost to follow-up. There was one infant death. 27/63 infants (43%) had post-natal surgery. More neonates requiring neonatal respiratory support/resuscitation had surgery compared to those who did not (67% vs. 29%, P=0.008). Patients with suspected CPAM or BPS on both initial and final ultrasound were more likely to have post-natal surgical management than when a lesion was no longer visible on final antenatal ultrasound (68% vs. 23%, P=0.001). Over 50% of antenatally suspected CPAM/BPS either regressed or had an alternate post-natal diagnosis. Perinatal outcome was good, with the majority of neonates/infants conservatively managed. Persistently visible antenatal lesion and need for neonatal respiratory support predicted ultimate surgical management.