Because the prognosis of giant cell arteritis (GCA) is related to the development of ischemic complications, we sought to assess the possible influence of traditional risk factors of atherosclerosis in the development of severe ischemic complications of GCA. We conducted a retrospective study of patients with biopsy-proven GCA diagnosed from 1981 to 2001 at the single hospital for a well-defined population of almost 250,000 people. Patients were considered to have severe ischemic manifestations if they suffered visual manifestations, cerebrovascular accidents, jaw claudication, or signs of occlusive changes in large arteries of the extremities. Patients were assessed for the presence of hypercholesterolemia, hypertension, diabetes mellitus, and heavy smoking at the time of GCA diagnosis. The presence of traditional risk factors of atherosclerosis at the time of GCA diagnosis in this series of 210 patients increased significantly the risk of developing at least 1 of the severe ischemic complications (odds ratio [OR], 1.79; 95% confidence intervals [CI], 1.03-3.11; p = 0.04). Patients with traditional atherosclerosis risk factors had fever less commonly than the rest of GCA patients (5.2% vs. 16.0%; p = 0.01). GCA patients with hypertension exhibited a significantly increased risk of developing severe ischemic complications (OR, 1.80; 95% CI, 1.00-3.25; p = 0.05). The current study suggests that the presence of atherosclerosis risk factors at the time of diagnosis of GCA may influence the development of severe ischemic manifestations of the disease.