Radioisotope uptake measurements and radioisotope scanning (scintigraphy) are used in the management of patients with hyperthyroidism. In this commentary, Franklin discusses the recent findings of Okosieme et al. that, in most patients, isotope studies do not provide any useful information in addition to that obtained from clinical examination and standard laboratory tests, and suggests that centres routinely performing these tests should evaluate their cost-effectiveness. J A Franklin, Clinical Endocrinology, DOI: 10.1111/j.1365-2265.2009.03633.x