Primary hyperparathyroidism (HPT1) is a common endocrine disorder, which is asymptomatic in 80% of cases. The diagnosis is ordinarily easily made, based on an inappropriately elevated parathormone level (PTH) in the face of hypercalcemia. In 85% of cases, HPT1 is due to hormone secretion from a single parathyroid gland (uniglandular disease) and the remaining patients have multiglandular disease. The best localization study is MIBI scintigraphy (methoxy isobutyl isonitrile) coupled with the results of a neck ultrasound exam (sensitivity >95%). Other investigations are reserved for patients with persistent or recurrent HPT1 post-surgery. Surgery is the only cure. The surgical approach may include a bilateral cervical exploration, a unilateral approach under local anesthesia, or focused minimally invasive (video-assisted or totally endoscopic) approaches. A decrease in PTH level measured intraoperatively of greater than 50% is predictive of cure in more than 97% of cases. Surgery is recommended even for moderate HPT1 and for very elderly patients because improvement in both the quality of life and bone density have been proven in these situations. The role of medical treatment is limited. Persistent or recurrent HPT1 requires a meticulous diagnostic approach and management in surgical centers with expertise. Persistent elevation of PTH postoperatively without hypercalcemia does not mandate further exploration. The prognosis of normocalcemic patients with elevated postoperative PTH levels remains uncertain.