Intracavernous carotid mycotic aneurysms are rare and management is dictated by clinical presentation. This case involved a patient presenting with a symptomatic expanding proximal internal carotid artery aneurysm treated with antibiotics and balloon occlusion but with thromboembolic complications resulting in a fatal outcome. Points of discussion include difficulties faced in reaching a diagnosis, management options for mycotic aneurysms and the rationale in this case for choosing endovascular rather than surgical treatment. The use and limitations of trial balloon occlusion are discussed as well as complications of vessel occlusion, in particular thromboembolism. Also discussed is the importance of surveillance imaging and the impact of sepsis on overall management.