A 54-year-old woman was found to have abnormal shadows on her chest radiograph taken on an annual medical examination. The chest radiograph showed multiple nodules in the bilateral middle and lower lung fields accompanied with bilateral hilar lymphadenopathy. A computed tomography of the neck and chest revealed nodules in her right middle lobe and bilateral lower lobes with an enlarged thyroid. A metastatic malignant disease involving both thyroid and lungs was suspected, therefore thyroid and lung biopsies were performed. The histological examination of the thyroid and the lung specimens revealed non-caseating epithelioid cell granulomas which were compatible with sarcoidosis. Although the thyroid involvement of sarcoidosis is rare, it should be included in the differential diagnosis with patients with thyroid swelling.