Carotid artery aneurysms account for 4% of peripheral aneurysms and may present as a neck mass, with hemispheric ischaemic symptoms, or with symptoms secondary to local compression. This case explores the presentation, investigations and management of a presumed mycotic common carotid artery aneurysm in a 77-year-old male, which was repaired using end-to-end interposition vein graft using long saphenous vein. This report discusses the aetiology, presentation and surgical management for carotid artery aneurysms, as well as focusing on that of the rare mycotic carotid artery aneurysm.