de Quervain thyroiditis is a self-limited inflammatory disorder of the thyroid gland. It is an uncommon disease in adults and very rare in children. Fritz de Quervain, a Swiss surgeon, who was an authority on thyroid disease, described the unique pathology of this disease. Granulomatous changes with giant cells in thyroid tissue are the pathological findings. Viral infection in genetically predisposed individuals has been proposed as the pathogenesis of the disease. Clinical hallmarks for the diagnosis are painful thyroid enlargement, elevated erythrocyte sedimentation rate, and C-reactive protein as well as decreased uptake of the thyroid gland on thyroid scintigraphy. In addition, thyrotoxicosis is present in about 50% of cases in early phase of the disease. Serum thyroglobulin level is usually elevated. Only symptomatic treatment with analgesics is usually required for pain relief. Glucocorticoid therapy may be used in severely ill patients. de Quervain thyroiditis is generally completely resolved without complications in 6-12 months. However, permanent hypothyroidism and recurrent disease have been reported in some patients.