Pretibial myxedema (PTM) is a asymptomatic localized thickening of the pretibial skin due to deposition of acid mucopolysacharides (glycosaminoglycans). PTM, Graves’ ophthalmopathy (GO) and thyroid acropachy are the triad of classic extrathyroidal manifestations of Graves' disease. PTM usually follows the onset of GO, and PTM develops after the diagnosis and treatment of hyperthyroidism. We report here on a 51-year-old female who presented with painful, well demarcated hyperpigmented plaques with nonpitting edema on both lower legs. The histopathologic findings showed an increased accumulation of mucin throughout dermis. In our patient, PTM was the earliest manifestation and this led to the diagnosis of Graves' disease.