Objective: To study the causes, characteristics and outcome of treatment of patients with primary hyperparathyroidism. Methods: This retrospective cohort analysis was conducted at the Jinnah Postgraduate Medical Centre, Karachi, and comprised data of patients with primary hyperparathyroidism between 2004 and 2014.. SPSS 17 was used for data analysis. Results: Of the 25 patients, 1(4%) was male and 24(96%) were female. The overall mean age was 41.72 +/- 15.9 years, with a mean duration of symptoms of 4.1 +/- 3.3 years. The mean pre-operative parathyroid hormone level was 879.48 +/- 793.51 pg/ml. Skeletal manifestations were reported in 17(68%) patients, whereas 4(16%) patients had renal stone disease. Besides, 2(8.0%) patients presented with severe abdominal pain, 1(4%) had asymptomatic hypercalcaemia and 1(4%) patient presented with headache and was diagnosed as parathyroid adenoma in the context of multiple endocrine neoplasia type 2A. All patients underwent parathyroidectomy. A solitary adenoma was reported in 23(92%) patients, carcinoma in 1(4%) and an adenoma with hyperplasia of other glands in 1(4%) patient. Conclusion: A high index of suspicion is required for early diagnosis of primary hyperparathyroidism.