BACKGROUND: The objective of the present study was to compare the silent form of giant cell arteritis (GCA) to the classic cephalic form of the disease. METHODS: We conducted a retrospective study based on a chart review of 50 consecutive, biopsy-proven GCA, recorded at a department of internal medicine. We sought to distinguish a silent form, defined by a prolonged inflammatory syndrome or fever of unknown origin with the absence of cephalic signs, polymyalgia rheumatica, or large artery involvement, from an overt "classic" cranial temporal arteritis. RESULTS: The prevalence of the silent form of GCA was 46% in our study. Abnormal temporal arteries were more frequent in the cephalic group. The silent GCA group had higher C-reactive protein levels (p<0.05), a higher platelet count (p<0.05), and lower serum albumin (p<0.05). There was no significant difference in temporal artery specimens in the two groups. Clinical relapses tended to be more frequent, and patients free of corticosteroids tended to be less frequent, in the cephalic group, though the difference was not statistically significant. CONCLUSIONS: The silent and cephalic forms of GCA could have distinct clinical and biological patterns and different outcomes. The limitation of our study was its retrospective design. Further studies are required to determine if this distinction is useful in treating GCA patients.