The surgical medical team at Prince Sultan Cardiac Center in Qassim successfully performed an urgent and high-risk open-heart surgery that ended the suffering of a 36-year-old woman. She was suffering from recurrent shortness of breath that worsened over time, accompanied by episodes of chest pain and palpitations. The detailed medical examinations showed the presence of a large mass occupying the left atrial cavity of the heart, which is attached to the mitral valve. This is consistent with one of the relatively rare benign tumors of the heart known as Amyxoma. The patient was carefully prepared for surgery and underwent a three-hour open-heart procedure. During the surgery, the large tumor mass measuring 12*9*8 cm was removed, along with the interatrial septum, and sent for histopathological study in the pathological anatomy laboratories. The interatrial septum was then reconstructed. After the successful operation, the patient was monitored in the cardiac surgery intensive care unit for 48 hours. then transferred to the surgical department under the supervision of the medical staff. After ensuring her condition was stable, she was discharged home in a stable condition. A regular follow-up plan was set up to monitor her progress at the surgical and cardiac clinics.