Mediastinal parathyroid tissue hyperfunctions in as much as 25% of the patients with primary hyperparathyroidism, and this may be responsible for causing conventional operative procedures to fail in as much as one-third of the cases. When lesions prove to not be accessible through a cervical incision, or when a mediastinal adenoma is diagnosed before cervical procedures, median sternotomy and angiographic ablation have been considered the only options for removal. However, thoracoscopy has theoretic advantages over both. Two patients underwent successful thoracoscopic removal of a hyperfunctioning ectopic mediastinal parathyroid adenoma and their cases are presented here.