Giant-cell arteritis frequently poses diagnostic and therapeutic challenges. This article summarizes recent investigations concerning diagnosis and treatment of giant-cell arteritis.Efforts to improve diagnostic accuracy have centered on serologic markers and imaging techniques. Although the erythrocyte-sedimentation rate, C-reactive protein, and platelet count continue to be the primary markers, others such as interleukin-6 and fibrinogen can provide additional information. High-resolution magnetic resonance imaging and angiography, fluorine-18-fluorodeoxyglucose positron emission tomography, and color Doppler ultrasonography can show findings relevant to the diagnosis of giant-cell arteritis. Recent inquiries suggest a steroid-sparing benefit from initiation of treatment with intravenous steroids. Adjunctive treatment with methotrexate may also provide this benefit. Aspirin appears to decrease likelihood of stroke or visual loss in giant-cell arteritis without increasing bleeding complications.An expanded repertoire of imaging techniques and serologic markers may supply information relevant to the diagnosis of challenging cases of giant-cell arteritis. Treatment modifications, including initiation with intravenous steroids, or addition of methotrexate or aspirin to the regimen, may decrease morbidity from disease, corticosteroid treatment or both.