Percutaneous arterial cannulation is systematically used in cardiac surgery and reanimation for hemodynamic monitoring. It was frequently used in coronarography. Risk factors for occurrence of radial aneurysm after catheterization may include advanced age, longer duration of catheterization, hospitalization duration, and general infection with Staphylococcus aureus. We report an uncommon case of radial artery aneurysm, after cardiac surgery. We operated the patient with a good result.