True absence of a branch pulmonary artery is rare. We identified a patient initially diagnosed with an absent left pulmonary artery at a previous hospital. Due to disagreement in the initial diagnosis, she had a diagnostic catheterisation, which revealed an isolated left pulmonary artery off the left innominate artery via a ductus. The ductus was recanalised with serial stenting and balloon dilatation followed by reanastomosis to the main pulmonary artery. In a patient who initially is diagnosed with an absent pulmonary artery, an alternative diagnosis, such as this case report, should be considered.
