Graves' disease, as known today, is an autoimmune, diffuse, chronic disease of thyroid gland, as described by Robert Graves in 1835. It presents genetic predisposition and unknown etiology evidence, which is influenced in its development by several factors, including environment (dietary iodine intake, stress, drugs and infections). The disease is characterized by one or more changes: hyperthyroidism, goiter, ophthalmopathy, skin changes and pretibial myxedema, around 5% less common, and other symptoms 90% to 95%. One of the most relevant clinical practice aspects in Graves' disease patients management is to distinguish Graves' disease in initial phase, from other types of destructive thyrotoxicosis, in addition to evaluate therapeutic methods and efficient follow up, as well as predict early recurrence or remission of disease. Scintigraphy with pertechnetate (99 mTc) and TSH levels dosage are considered the choice for this purpose. However, they present some technical difficulties, as they are not widely available and have contraindications. In this scenario, thyroid color-flow doppler ultrasonography (US Doppler) presents a viable alternative, as a widely available, low cost, non-invasive and radiation free method, providing initial diagnosis and patients with Graves' disease follow up. In adittion, this method is used in differential diagnosis with other causes of thyrotoxicosis in the early stage.