Background <p>Aortic pseudoaneurysm secondary to <i>Mycobacterium tuberculosis</i> infection is exceedingly rare. Extrinsic compression of the left main coronary artery by an aortic pseudoaneurysm is also uncommon, and cases attributable to tuberculosis are particularly rare. This report describes a mid-ascending aortic pseudoaneurysm causing left main coronary artery compression resulting in cardiac arrest in a patient with a history of tuberculosis, which was successfully managed with emergent surgical intervention.</p> Case presentation <p>A 76-year-old man with a history of tuberculosis and radiologic findings suggestive of previous tuberculous disease experienced cardiac arrest prior to transfer and was referred to the authors’ institution. Coronary angiography, performed because of chest pain and elevated cardiac biomarkers, demonstrated extrinsic compression of the left main coronary artery by an ascending aortic pseudoaneurysm. Return of spontaneous circulation was achieved after approximately 48 min of cardiopulmonary resuscitation. Upon arrival at our emergency department, computed tomography revealed a 6-cm pseudoaneurysm of the proximal-to-mid ascending aorta. Emergent surgical resection of necrotic ascending aortic tissue and graft replacement of the ascending aorta were performed, and the postoperative course was favorable.</p> Conclusion <p>Ascending aortic pseudoaneurysm may cause sudden cardiac arrest through extrinsic compression of the left main coronary artery. In patients with a history or radiologic evidence of tuberculosis, tuberculosis-related involvement may be considered, but definitive surgical treatment should not be delayed in life-threatening presentations.</p>