In a prospective study of 74 patients and a retrospective study of 35 patients with polymyalgia rheumatica/giant cell arteritis steroid related side effects occurred in at least one third of patients, and in two thirds if weight gain was included. Side effects were significantly related to an initial prednisolone dose of more than 30 mg and to the cumulative prednisolone dose. Patients taking a mean daily dose of 5 mg prednisolone or less were significantly less likely to develop side effects.