Though several studies have emphatized the diagnostic potentialities of color duplex sonography (CDS) in giant cell arteritis (GCA) bipsy remains the gold standard for the diagnosis. Recently it has been suggested that the dark hypoechogenic halo is strongly related to the acute phase of the disease so CDS of the temporal artery may be a useful tool in monitoring and assisting glucocorticoid tapering in patients with GCA. To date, acute phase reactants generally used for this purpose but they are not absolute indicators of disease activity. The aim of our study was to evaluate the role of color duplex ultrasonography in diagnosis and follow-up in patients with GCA