In clinical practice, physicians often encounter patients with persistent elevated serum parathyroid hormone levels and normal serum calcium levels, a state known as normocalcemic hyperparathyroidism (NHPT). The investigation of NHPT cases can lead to unnecessary use of parathyroid scintigraphy (PS) and consequently unnecessary health-care costs. In this clinical review, the most common causes of NHPT and the possible indications for PS performance in such cases are mainly presented and discussed.