We report a rare case of left atrial paraganglioma with a synchronous carotid body paraganglioma in a 30-year-old man with succinate dehydrogenase B gene mutation. The patient initially presented with a neck mass and palpitations. Laboratory test results showed elevated catecholamine levels. A cardiac paraganglioma was identified by computed tomography, meta-iodobenzylguanidine scintigraphy, and magnetic resonance imaging. Surgical resection of both paragangliomas were performed on two separate occasions. Serum and urine catecholamine levels returned to normal range. On follow-up, there was no recurrence of the cardiac paraganglioma. Radiotherapy was subsequently initiated for recurrence in the carotid body paraganglioma.