Atrial septal aneurysm (ASA) is an uncommon but wellrecognized cardiac abnormality. This educational text reviews the case of a 54-year-old female presenting an ASA related to a small ostium secundum atrial septal defect. The considerable signs and symptoms, interestingly, have not been justified by the clinical and hemodynamic investigations. So, we opted for a better imaging investigation with cardiac catheterization and transesophageal echocardiography. The surgical process was earlier indicated and performed with aid of cardiopulmonary bypass.