BACKGROUND Parathyroid glands are endocrine glands that regulate calcium metabolism. Usually four in number, they lie mostly on the posterior aspect of thyroid glands. Primary hyper-parathyroidism (PHPT) refers to a condition wherein they secrete an excess of parathyroid hormone leading to signs and symptoms of hypercalcemia. PATIENTS AND METHODS Thirty-two patients of primary hyper-parathyroidism were seen by us in the ten years. Majority of patients were below 40 years of age (88%). Male: female ratio was 1:4. The diagnosis was made incidentally in patients who reported for various signs and symptoms not responding to treatment. High serum calcium pointed to the diagnosis of primary parathyroid hyperplasia. It was confirmed by high level of serum parathyroid hormone and localization of enlarged parathyroid glands by USG / MRI and / or Tc-99 Technetium scan. Of the 32 patients examined, 43 parathyroid glands were excised, five cases had two glands excised; out of these 4 cases underwent parathyroid reimplantation in neck/forearm muscles. One unusual case underwent operation for giant-cell tumor of the head of humerus. This patient presented with excessive vomiting not responding standard medical management in post-operative period. RESULTS During investigations serum calcium was found to be very high, the diagnosis was confirmed by finding high parathyroid hormone and corroborated by T(99) Technetium scan. Parathyroidectomy was done in all cases, of which 59% (18 cases) developed mild to severe tetany due to hypocalcaemia. CONCLUSION Primary hyperplasia of thyroid gland is the most important cause of hypercalcemia. Hypercalcemia is found in all cases of PHPT in our series with high parathyroid hormone levels. Majority of our cases have one gland involvement and hypocalcaemia in our series is unusually high following excision of involved gland.