Precise localization of hyperfunctioning parathyroid tissue is critical for the successful surgical management of primary and tertiary hyperparathyroidism and is arguably also useful in patients with secondary hyperparathyroidism. Conventional imaging techniques such as ultrasound (US) and [99 m]Tc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) are widely used, but their sensitivity and specificity may be limited in complex cases, including small adenomas, ectopic glands, multiglandular disease, and post-surgical necks. Positron emission tomography (PET) using [18F]fluorocholine (FCH) as radiotracer has emerged as a first-line alternative to conventional imaging with SPECT/CT. While most centers currently perform this modality as PET/CT, the fortunate few equipped with a PET/magnetic resonance (MR) scanner are uniquely positioned to scan patients with exceptionally high anatomical detail and a very low radiation burden, originating solely from the PET component. This approach combines the metabolic sensitivity of PET with the excellent soft-tissue contrast of MR, enabling accurate detection and precise anatomical localization of diseased parathyroid glands. Given that parathyroid diseases are almost exclusively benign and can be effectively imaged with a limited acquisition range covering only the neck and upper mediastinum, they likely represent one of the most suitable applications for PET/MR. This chapter reviews the principles, radiotracers, protocols, interpretation strategies, clinical applications, and future directions of PET/MR in parathyroid imaging, with an emphasis on [18F]fluorocholine PET/MR.