A 58-year-old white male with a history of stroke and deep vein thrombosis presented with an interatrial intraseptal mass. Cardiac-computed tomography demonstrated a thin-walled, well-demarcated cyst in the inferior border of the fossa ovalis protruding into both atria. Removal of the interatrial intraseptal cyst was performed using a minimally invasive three-dimensional endoscopic periareolar approach.