A previously healthy male was diagnosed with a malignant thymoma. During the workup, he had syncope, which was due to severe unrecognized hypocalcemia. Additional workup was suggestive of parathyroid failure. In particular, there was no evidence of autoimmune parathyroid failure due to antibodies against the calcium-sensing receptor. Literature review reveals one additional thymoma case with these clinical features of chronic hypoparathyroidism of unknown cause.