Primary hyperparathyroidism is rare in the pediatric population and is typically caused by a single parathyroid adenoma. Parathyroid adenomas are almost always small and not palpable on exam but can be evaluated by neck ultrasonography or 99 m Tc-sestamibi scan. Surgical resection is the only curative treatment. In this case, a 16-year-old male presents with a 10-day history of nausea, vomiting, and headaches and is found to have a highly elevated calcium and parathyroid hormone level and a cerebral calcification in his frontal lobe noted on computed tomography. He had a palpable mass over the region of his left inferior parathyroid gland which was surgically resected with histopathology revealing a giant parathyroid adenoma. Giant parathyroid adenomas are exceptionally rare in children and adolescents and are more likely to present with severe hypercalcemic crisis than smaller adenomas. As early symptoms are often nonspecific, awareness of this clinical entity is important. There are several reports of basal ganglia calcifications in the setting of parathyroid adenoma, but, to our knowledge, this is the first report of a patient with frontal lobe calcification.