We report the case of a 48 year old male with human immuno-deficiency virus and hepatitis C virus infection and previous grafting of a thoracic aortic aneurysm. He returned from a trip to India with fever and in a poor physical condition. Diagnostic work-up revealed septicaemia with staphylococcus aureus, infection of the aortic graft with covered rupture of the proximal anastomosis and mitral valve endocarditis. Following antibiotic therapy, implantation of a transcutaneous endovascular aortic prosthesis and mitral valve repair were performed. During the postoperative period, the patient complained of pain and a palpable pulsating mass in the right cubital fossa. Ultrasound scan revealed a pseudoaneurysm at the brachial artery bifurcation. Since there were no signs of venous puncture in this area, we assumed this to be a mycotic pseudoaneurysm resulting from septic embolism. In the absence of clinical signs of inflammation, this pseudoaneurysm was successfully treated by ultrasound-guided thrombin injection. Irrespective of the cause for this mycotic pseudoaneurysm of the brachial artery, percutaneous ultrasound-guided thrombin closure in combination with antibiotic therapy might be a feasible, safe, cheap and minimally-invasive alternative to surgery.