The most common cause of chronic hypercalcemia is primary hyperparathyroidism (PHPT). However, owing to the diverse presentation of hypercalcemia, the diagnosis often goes unnoticed culminating as a continuum of recurrence of symptoms. Nephrolithiasis, decreased bone mineral density and peptic ulcer disease are the main clinical sequelae. Among the causes of PHPT 80% are caused by parathyroid adenomas (PA). However, only rarely, these adenomas are found ectopically.We present the case of a 66-year-old female with a history of recurrent renal stones and peptic ulcer disease. She was found to have elevated serum calcium and PTH levels. However, subsequent high resolution CT scan of chest and neck failed to demonstrate any abnormality. Therefore, an anterior planar Technetium-99m-sestamibi (MIBI) scintigraphy scan using a single-tracer was done and it identified ectopic anterior mediastinal parathyroid adenoma. The patient was successfully managed with video-assisted thoracoscopic surgery and excision of the mass with follow up calcium level monitoring.An elevated calcium level should prompt a thorough workup, as sometimes it's the only clue to the unrelated and diversified systemic manifestations of hypercalcemia. Hyperparathyroidism due to ectopic adenoma is quite rare and possess a diagnostic and management challenge.Symptomatic hypercalcemia and high level of PTH without local PA should alert physicians to search for ectopic locations through imaging. VATS is a safe and effective minimally invasive procedure for the resection of ectopic mediastinal PA and it should be considered as the first line approach for resection of these ectopic tumors.