Ectopic parathyroid glands tend to be located in positions defined by their embryologic path during fetal development. We describe such a case of primary hyperparathyroidism due to ectopic retropharyngeal parathyroid adenoma (PTA) in a teenage girl with mild symptomatology. The initial workup with scintigraphy showed suspicious uptake above the level of thyroid gland, ultrasound, and computed tomography failed to localize an adenoma. Magnetic resonance imaging precisely localized an ectopic retropharyngeal PTA, which led to successful surgical removal.