Parathyroid adenoma is a rare disease, mostly benign. The diagnosis is often confused or missed due to variabe clinical manifestations in different specialties. The standard treatment is surgical remove. Objective: study the clinical manifestations, laboratory findings and surgical treatment outcome. Methods: 20 patients suffering from parathyroid adenoma treated with surgical removal. Descriptive retrospective study. Results: average age 47.8. The clinical manifestations are mainly renal signs, bone and non-specific signs like fatigue, weight loss, polydipsia... All have hypercalcemia, elevate PTH The sensivity of ultrasound and Tc 99m sestamibi scan can localize the tumor in 70-80 percent. Frozen section helps to confirm the tumor removed. All patients have a decrease more than 50 percent intraoperative PTH 10 minutes after tumor extirpation. PTH level is normal after 24 hours and Calcemia returns normal after 3 days. Conclusion: the manifestations of the parathyroid adenoma is very variable with non-specific signs. Diagnosis is based on hypercalcemia and elevated PTH Scintigraphy is an useful tool, high sensivity, specificity. Minimally invasive parathyroidectomy assure successful outcome.