The last therapeutic alternative in severe postsurgical hypoparathyroidism is allotransplantation of microencapsulated parathyroid cells. With this technique, it is possible to implant cells or tissue of parathyroid origin to replace them in such patients, without immusupression. We report an allotransplant of parathyroid tissue in a patient with continous endovenous requirement of calcium to survive. The microencapsulation was carried out with a commercial sodium alginate. We implant 23 microspheres in the nondominant forearm and 40 microspheres in the leg in a second attempt. In this article, we show functionality of the graft for at least 20 months without requirement of endovenous calcium. We report this procedure as a therapeutical alternative in severe hypoparathyroidism.