The aim of this study was to present our 20-year experience regarding primary hyperparathyroidism (PHPT). PHPT patients who underwent parathyroidectomy in our clinic were reviewed retrospectively. There were 190 PHPT patients, of whom 137 were asymptomatic (72%). The mean serum calcium at the time of diagnosis was 11.9 +/- 2.2 mg/dL. The mean parathyroid hormone (PTH) level was 467 +/- 78 pg/mL. Ultrasonography (USG) identified all abnormal glands accurately (82.6%) and Technetium-99m sestamibi scintigraphy (MIBI) was used in 89.4% of the patients and magnetic resonance imaging (MRI) in 61%. The common use of USG and MIBI detected 92% of the lesions. Bilateral neck exploration (BNE) was performed in 12.2% of the patients and focused unilateral neck exploration (FUNE) in the remaining 87.8%. Surgical intervention was unsuccessful in 1 patient (0.5%). The conversion ratio from FUNE to BNE was 5.2%. The mean operation time and mean hospital stay decreased significantly in patients with FUNE. Pathologic examination revealed single adenoma in 93% of the patients. New imaging techniques result in the conversion of surgical treatments of PHPT. FUNE in parathyroidectomy performed by an experienced surgeon may provide successful treatment rates.