Twenty-seven patients with severe alopecia areata were treated with dapsone. The results of a mean treatment duration of 10 +/- 0.5 months are reported, and compared with the results of long-term topical immunotherapy obtained previously at the same institute. The efficacy of dapsone proved to be markedly inferior to that of topical immunotherapy. The percentage of patients showing regrowth of hair during treatment with dapsone was comparable with the occurrence of spontaneous regrowth of hair reported in the literature.