Hypoparathyroidism is a common complication of total thyroidectomy. Due to their small size, variable anatomical position, and potential resemblance to the surrounding tissue, intraoperative localization of the parathyroid glands can be challenging. During thyroidectomy, the parathyroid glands need to be dissected off the thyroid and left in situ, which puts them at risk of being directly damaged, inadvertently removed, or having their vasculature injured. In 5-15% of patients, the vascular supply to all four glands is at risk when total thyroidectomy is performed. In 2011, autofluorescence of the parathyroid glands has been discovered by a team in Vanderbilt, Nashville. This unique autofluorescence property of the parathyroid glands which occurs at around 820 nm when excited by light at 785 nm, can be used to identify the parathyroid glands. Since this discovery, probe-based and camera-based devices that easily distinguish the parathyroid glands from the surrounding tissues have been developed. Image-based devices can also use indocyanine green (ICG) dye, which enables visualization of parathyroid-gland vessels and perfusion. Mapping angiography involves ICG injection at an early stage of dissection to visualize the vascular pedicle of the parathyroid glands and help preserve the vascular supply. Perfusion angiography estimates the perfusion of the remaining parathyroid glands based on ICG uptake on fluorescence imaging after thyroidectomy. The assessment of perfusion and thus viability of glands using ICG correlates with postoperative function. These new techniques to help detect and preserve parathyroid function during thyroidectomy will be described during this keynote lecture.