Hypocalcemia is relatively uncommon paraneoplastic syndrome. Only one case of hypocalcemia has been reported in a patient with chondrosarcoma. We herein report a case of a 32-year-old woman with metastatic chondrosarcoma with tetany. Her imaging findings revealed multiple calcific metastatic lesions in the lungs, pancreas, left atrium, and pulmonary vein. A laboratory examination showed hypocalcemia with no evidence of any other disease that could induce hypocalcemia. On the basis of the laboratory and clinical findings, we concluded the etiology of her severe hypocalcemia to be excessive calcium consumption by the tumor itself.