Takayasu's arteritis (TA) is a rare granulomatous vasculitic disease that affects the aorta and its major branches. Recent studies have suggested that anti-TNFα biological therapies are highly effective in treating TA refractory to conventional immunosuppressive therapy. We describe two patients with TA: one with progressive TA despite management with two different anti-TNFα agents, infliximab and adalimumab, and another who developed TA while treated with infliximab for the management of pre-existing Crohn's disease. From our observations, we believe that a multicentered randomized study should be designed to assess the extent of resistance to these agents when different therapeutic doses are employed for managing TA.