Ninety patients with giant cell arteritis were followed up 9-16 years (median 11.3 years) after diagnosis. The mean duration of corticosteroid therapy was 5.8 years (range 0-12.8 years). Together, the patients had received corticosteroids for 492 patient-years. Five years after diagnosis, 43% of the patients were on corticosteroid therapy. After 9 years, 15 of 60 surviving patients (25%) were still being treated with 1.25-10 mg of prednisolone daily (median dose 5 mg). The relapse rate was about 50%, regardless of the time after diagnosis, when an attempt to withdraw the treatment was made. Forty-six per cent of the relapses occurred within one month and 96% within one year of the end of treatment. Most of the flare-ups occurred during the first year of therapy and in 55% of the patients on a prednisolone dosage of 5 mg or less. We did not find any increase in morbidity in our patients compared to the general population. Nor did we see any significant complications which we could attribute to the steroid treatment.