Primary hyperparathyroidism (HPT) is one of the most common endocrine disorders. The standard treatment is surgical removal via a cervical incision. In rare cases, abnormal parathyroid tissue may be present in the mediastinum and therefore inaccessible through the standard incision. A 57-year-old female presented in our clinic with high ionized calcium and high parathyroid hormone levels. A technetium-99m sestamibi scan showed a focal mass in the superior mediastinum. A single-stage cervical exploration and video-assisted mediastinoscopic (VAM) removal of the intrathoracic ectopic parathyroid adenoma was performed. Our approach proved to be successful. There were no surgical complications and the patient was discharged on postoperative day 2. We suggest that in the case of occult mediastinal hyperfunctioning parathyroid tissue, a VAM is a valuable extension of the standard explorative neck surgery.