Brachiocephalic vein aneurysm is an extremely rare clinical entity, with a limited number of case reports in the literature. We report the case of a 74-year-old woman with a left brachiocephalic vein aneurysm (3 × 3 × 6.5 cm) that was discovered fortuitously by contrast-enhanced chest computed tomography. Surgical intervention was performed simultaneously during tricuspid valve surgery with coronary artery bypass grafting. This paper discusses the details of our case, the surgical treatment of brachiocephalic vein aneurysms, and the different treatment options.