Warm thyroid nodules are a diagnostic modality after thyroid nuclide scanning. Iodine-131 nuclide classifies thyroid nodules into hot nodules, warm nodules and cold nodules according to the amount of nuclide taken up by the nodules, and this classification lacks specificity for the diagnosis of benign and malignant thyroid gland and has little diagnostic value. Because both benign nodules and thyroid cancer can manifest as cold nodules, they are of diagnostic value only for autonomously high-functioning adenomas of the thyroid, in which warm nodules are not evident in the peripheral and contralateral thyroid, and these nodules are also almost always benign. Nowadays, the diagnosis of thyroid nodules relies on ultrasound and palpation of the thyroid gland, which is further combined with medical history, clinical manifestations and serological laboratory tests to assess the benignity and malignancy of the nodules.