A case of intrathoracic retrotracheal goiter in a 40-year-old woman is herein described. A computed tomographic scan, magnetic resonance imaging and endoscopical ultrasonography all confirmed the existence of a retrotracheal encapsulated lesion, which was suspected to be aberrant mediastinal goiter. Radioiodine scintigraphy, however, demonstrated little uptake in the mass. A large (7 x 6 x 4 cm), encapsulated adenomatous goiter was then easily removed via a right thoracic approach.