Unilateral pulmonary artery agenesis (UPAA) is a rare congenital anomaly usually diagnosed in infancy due to associated cardiovascular malformations. We report a rare case of isolated right UPAA that presented atypically in adulthood with massive haemoptysis requiring a pneumonectomy. This case highlights the importance of maintaining a high clinical suspicion, the role of CT angiography and a multi disciplinary approach. Optimal management is often surgical however bronchial artery embolization (BAE) remains a useful adjunct.