Subtraction scintigraphy with 99mTc-pertechnetate and 201Tl-chloride is widely used for localizing the parathyroid gland, but the sensitivity of this method averages only 55%. The sensitivity of scintigraphy is improved by using a combination of 99mTc-sestamibi and iodine-123. Parathyroid adenomas can also be localized with 99mTc-sestamibi alone by subtracting early images from late sequential images. The fast washout of 99mTc-sestamibi from the thyroid gland allows visualization of the parathyroid gland. The purpose of this essay is to illustrate the findings of abnormalities of the parathyroid glands when using a combination of 99mTc-sestamibi and iodine-123.