34-year-old male with history of recurrent atrial fibrillation (AF) and mitral stenosis, status post radio-frequency ablation (RFA) and prosthetic mitral valve replacement two years earlier was admitted with prosthetic valve thrombosis for redo mitral valve surgery. During the surgery, a 2 x 1.5 x 1 cm mass was identified on the interatrial septum, attached to the edge of tricuspid valve's septal leaflet by a stalk. The mass was excised and histological evaluation revealed myxoma. It is accepted that myxomas can develop after cardiac trauma. It is known that RFA for AF increases the risk of thrombus or endocarditis in the atrium. Herein, we report a myxoma case where we think the heat energy caused by RFA might have triggered the development of the tumor.