The authors report their experience of Horton's disease in 47 histologically confirmed cases treated between 1966 and 1979. The symptomatology is recalled with the incidence of the various clinical and biochemical signs. The actuarial survival curve shows a 71.2 p. cent three year and a 61 p. cent five year survival rate. There was no statistically significant difference at three years with a control population. The duration of maintenance therapy was, on average, of 24.8 months, never less than 15 months and sometimes reaching 60 months. The average maintenance dose was 12 mg. Specific and non-specific complications are discussed. The incidence of refractory and cortico-dependent forms shows that the optimal treatment for this disease has yet to be found; the often brilliant initial results of corticotherapy do not reflect its long-term efficacy.