Vascular complications after total knee arthroplasty include arterial occlusion, arterial severance, arteriovenous fistula, and arterial aneurysm. Both a false aneurysm and a true aneurysm of the popliteal artery are described. The false popliteal aneurysm resulted from direct surgical trauma and required excision and repair. The true popliteal aneurysm was unsuccessfully treated with excision, transfemoral thrombectomy, and bypass surgery. Many of the vascular complications after total knee arthroplasty may be preventable and the following prudent guidelines are suggested. Careful preoperative evaluation is critical, including past medical history, palpation of pedal pulses, and review of radiographs to identify abnormal calcification in the vessels. Vascular consultation may be necessary. Should a vascular complication occur, immediate intervention with the advice and assistance of a vascular surgeon is imperative.