Parathyroid pathology comprises primarily hyperfunctioning lesions such as adenomas, hyperplasia, and, more rarely, carcinoma, which lead to dysregulated secretion of parathyroid hormone and alterations in calcium homeostasis. Among advanced molecular imaging techniques (single-photon emission computed tomography, SPECT, and positron emission tomography, PET), 11C-methionine positron emission tomography/computed tomography (PET/CT) enhances lesion localization by targeting increased amino acid transport and metabolic activity of abnormal parathyroid tissue, proving to be especially valuable when conventional ultrasound and scintigraphy are inconclusive. This imaging modality may be a helpful tool for evaluating parathyroid disease, particularly in patients with primary hyperparathyroidism (HPT) and challenging preoperative diagnostic scenarios.