Sixty seven patients were included, with an average age of 50 years (+/- 11.9), 15 men and 52 women. Greatest frequency of PHPT was observed in patients between 40 and 60 years of age. Average calcium value was 11.7 mg/dl (+/- 1.23) and that of PTH was 194.5 pg/ml (+/- 93). Histopathologic diagnosis was adenoma in 56 (83.58%), hyperplasia in 9 (13.43%), and carcinoma in 2 (2.9%) patients. Cure of the disease was achieved in 65 patients (97%). PHPT is a surgically curable disease; it is necessary to confirm diagnosis and decide on surgical treatment in accordance with established criteria even if the disease is asymptomatic.