Patients with pulmonary atresia require several investigations and operations. The role of magnetic resonance imaging in assessing the anatomy of the central pulmonary arteries, the origin and course of systemic collateral arteries, and the patency of surgical shunts has been studied with the aim of reducing the need for invasive angiography. Transverse, coronal, and sagittal images were obtained in ten adult patients and assessed without knowledge of surgical and angiographic data. Central pulmonary artery anatomy varied from full development to complete absence. Transverse slices showed hypoplastic arteries particularly well and the findings accorded with surgical and angiographic data in all patients. The origin and proximal course of 15 large collaterals were identified on the magnetic resonance images and 18 were identified by surgical and angiographic data. Magnetic resonance imaging did not show their distal connections; if such information is required angiography will be needed. Five surgical shunts were shown to be patent and two occluded at surgery and angiography, and this was confirmed on the magnetic resonance images. The patency of a further four shunts was uncertain, but they were not seen by magnetic resonance and were presumed to be occluded.