A 51-year-old male patient diagnosed with medullary thyroid carcinoma (MTC) in 2001, with progression to lung metastases following adriamycin therapy, was then successfully treated with dimethyltriazenoimidazole carboximide. He remained in partial remission for 7 years following numerous chemotherapy attempts to induce partial remission. In October 2008, the patient, then 58 years old, relapsed with numerous tumors throughout his central body. On December 1, 2008, the tumor marker for MTC, calcitonin, was at 38,611 pg/ml, i.e., much higher than the norm of <20 pg/ml. Since all other chemotherapy attempts had failed, he was ineligible for any new studies. Subsequently, the patient was immediately started on 10 mg/kg of dichloroacetate (DCA). By April 2009, the calcitonin level was reduced to 2,000 pg/ml. In May 2009, a new positron emission tomography showed a dramatic reduction in all tumor locations. The patient presently remains in remission and continues receiving the same dosage of DCA, with his tumor marker remaining stable in laboratory data since November 2009.