Giant cell arteritis is a rare, poorly understood, and often misdiagnosed entity. A case is reported of giant cell arteritis in a 30-year-old white male who developed severe bilateral peripheral claudication affecting both legs. The erythrocyte sedimentation rate (ESR) was markedly elevated. The diagnosis of vasculitis was established by histology postoperatively following exploration of both superficial femoral arteries and the placement of a reversed saphenous vein bypass graft to the right leg. Biopsy of the temporal artery revealed no pathology. The patient has been completely asymptomatic postoperatively and has resumed all previous normal activities. This condition has persisted in spite of a failed graft determined by an arteriogram performed 3 months after surgery. He has been treated with steroids continuously since the procedure.