Coexistence of primary hyperparathyroidism and acute pancreatitis has widely been reported in literature, but a causal relationship remains controversial. A case of acute pancreatitis as a first symptom of primary hyperparathyroidism with severe hypercalcemia is reported. In this patient a reduction of serum calcium level was obtained with medical therapy and resulted in the resolution of acute pancreatitis symptoms within 10 days. At the same time a parathyroid adenoma was clinically identified and elective parathyroidectomy was performed with complete normalization of intact parathyroid hormone and serum calcium level. At three-year follow-up, no recurrence or complications of pancreatitis were documented. The presented case suggests a cause and effect relationship between acute pancreatitis and severe hypercalcemia which should be kept in mind in the differential diagnosis of non-biliary, non-alcoholic acute pancreatitis. Reduction of hypercalcemia with medical treatment can represent a good chance for elective surgical neck exploration.