Acute pancreatitis as a first manifestation of primary hyperparathyroidism (PHPT) caused by parathyroid adenoma is exceptionally rare. A 21 year old man presented with severe abdominal pain, nausea and vomiting. Laboratory studies revealed leukocytosis of 15.3 thousand/μL, hemoglobin 14.4 g/dL, creatinine 1.31 mg/dL, amylase 1,148 IU/L, lipase 862 IU/L. Serum calcium level was 14.6 mg/dL, intact parathyroid hormone (iPTH) level was 629.6 pg/ mL. Neck ultrasound showed a 1.5 × 1 × 1.1 cm solid mass at the posterior inferior aspect of the right thyroid lobe. Parathyroid scan showed a focal area of activity in the right lower lobe suggesting a parathyroid adenoma. The patient underwent parathyroidectomy and pathological examination of the parathyroid gland confirmed a parathyroid adenoma. Although the actual causal relationship between hypercalcemia and pancreatitis has been a persistent topic of debate, detection of hypercalcemia may be a clue to diagnose PHPT due to parathyroid adenoma. After aggressive medical management of acute pancreatitis, parathyroidectomy may improve clinical outcome and prevent further recurrences of pancreatitis.