OBJECTIVE: To report a rare case of primary hyperparathyroidism presenting with hyperparathyroid crisis due to parathyroid hyperplasia with ectopic glands. METHODS: We present the initial clinical manifestations, laboratory results, radiologic and surgical findings, and management in a patient who had hyperparathyroid crisis. The pertinent literature and management options are also reviewed. RESULTS: A 60-year-old female presented with hyperparathyroid crisis requiring preoperative stabilization with rehydration, diuresis, bisphosphonate therapy, and ultimately hemodialysis. Parathyroidectomy revealed asymmetric 4-gland hyperplasia, with a massive ectopic parathyroid gland in the tracheoesophageal groove extending into the mediastinum. Her postoperative course was complicated by hungry bone syndrome and hypocalcemia. CONCLUSION: This case illustrates the rare occurrence of hyperparathyroid crises due to asymmetric parathyroid hyperplasia with a massive ectopic parathyroid gland.