Primary hyperparathyroidism occurs in a significant number of patients over 60 years of age; about one-third of the 182 patients we studied were in this age group. Primary hyperparathyroidism has been recognized with greater frequency in recent years, particularly in patients without manifestations of renal lithiasis or osteitis fibrosa cystica and in older patients. Age alone is not critical in the occurrence of serious complications from hypercalcemia, the presence of other life-endangering disease, or the development of major postoperative complications in the management of primary hyperparathyroidism. A liberal but selective policy is advocated in advising operation for primary hyperparathyroidism in the elderly. Different clinical patterns of primary hyperparathyroidism are recognized in all age groups. The operative procedure for primary hyperparathyroidism is determined primarily by the surgeons at the time of operation, on the basis of gross characteristics of the parathyroid glands. A precise correlation is not found between microscopic changes, gross changes, and clinical features of primary hyperparathyroidism.