Two hundred bilateral temporal artery biopsies performed prospectively in 200 patients suspected of having giant cell arteritis (GCA) were always preceded by Doppler flow study and local clinical examination. If bilateral temporal artery biopsies had been guided by positive local clinical examination, 24 positive biopsies would have been found, and Doppler studies would have improved the diagnostic score to 39; however, the biopsies gave 42 histologically positive results, providing the best diagnostic yield. The possibility of GCA with normal Doppler flow studies was noted as well as the existence of relatively asymptomatic forms of GCA, so that systematic performance of bilateral temporal artery biopsy would seem justified in any case of suspected GCA.