Twenty-five percent of primary hyperparathyroidism is caused by ectopic mediastinal parathyroid glands, with 2% of these not accessible to standard cervical surgical approaches. Advancement in video-assisted thoracoscopic surgical techniques has decreased the need for sternotomy to successfully remove these ectopic glands. The thoracoscopic approach, however, is limited by the surgeon's inability to always accurately visualize ectopic glands. Intraoperative radionuclide-guided dissection, using a thoracoscopic approach, provides a novel adjunct to the removal of occult ectopic parathyroid glands. We report a case of an occult ectopic parathyroid adenoma removed thoracoscopically using an intraoperative handheld gamma probe.