The three most striking features of temporal arteritis (TA) are the high incidence in populations of Nordic origins, the remarkable rarity of the disease among persons younger than 50 years, and the predilection for the superficial temporal arteries. At present, neither genetic susceptibility, environmental factors nor occurrence of specitic infections offer complete explanations to why Scandinavians are at increased risk of contracting TA. Similarly, recent developments in immunology and pathology of inflamed arteries cannot explain the preference of TA for this particular medium-size artery or why the disease almost exclusively affects persons older than 50 years. Although significant contributions regarding the pathogenesis of TA during the last decade are encouraging, the etiology of this disease still remains an enigma.