Tectnetium-99m sestamibi imaging for parathyroid adenoma localization has been performed using both dual-tracer subtractipn and dual-phase single tracer washout techniques. Initial administration of 250 uCi of I-131 orally twenty for hours before scanning with immediate injection of 15 to 20 mCi Tc-99m MIBI followed by anterior neck and mediastinum scanning for 300 K count in the 364 and 140 KeV with 20%energy window. The I-131 image was subtracted from Tectnetium-99m sestamibi image. Of the fourteen patients having parathyroid adenoma 12were localized by the subtraction technique (85.71%) while the dual-phase technique could detect 10 out of 14 glands (71.42%) with a statistically significant difference (p<0.05). Dual-tracer subtraction parathyroid adenoma imaging is superior to dual-phase imaging.