Thyroid cancer is comparatively rare. Thyroid nodules, on the other hand, are frequently diagnosed as a result of increasing use of diagnostic imaging. Cytological investigation of small nodules that have been found by chance often reveals micropapillary carcinoma that is probably not clinically relevant. The new guideline 'Thyroid cancer' advises that cytological investigation of these non-palpable, incidentally discovered thyroid nodules should only be performed on indication. The standard treatment for patients with papillary or follicular thyroid cancer consists of thyroidectomy followed by, if indicated, lymph-node dissection, ablation therapy with radioactive iodine and TSH-suppression. The extent of this treatment is determined on the basis of known prognostic factors and the results of initial treatment. Targeted systemic therapy is available for patients with metastatic progressive disease. There is more focus on the effects of short- and long-term treatment, in order to optimise quality of life.