Cyclosporin has been shown to be effective in the treatment of adult atopic dermatitis, but there are no clinical trials evaluating its use in childhood. Atopic dermatitis is more common in children and the severe form can be associated with considerable morbidity. We report on 18 children with severe refractory atopic dermatitis who have been treated with cyclosporin on an open basis. The drug was given at an initial daily dose of 5 or 6 mg/kg and in some patients the dose was reduced according to response. Sixteen patients showed a good or excellent response to treatment, one a moderate response and one patient failed to improve. The treatment was well tolerated and there were no significant changes in serum creatinine or blood pressure. Long remission after withdrawal of treatment was seen in some patients, although most relapsed within a few weeks. We suggest that cyclosporin is an effective and safe short-term treatment for severe atopic dermatitis in childhood.