Topical squaric dibutylester (SADBE) is currently used in Europe to treat alopecia areata in adults. We attempted to determine this drug's effectiveness and convenience in treating children with severe alopecia areata who are psychologically disturbed and resistant to other therapies. Twenty-eight children under 13 years of age who had extensive and long-standing alopecia areata and were not responsive to conventional therapies were sensitized on the head with 2% SADBE in acetone and treated with weekly applications for 12 months. Nine patients (32.1%) achieved complete or cosmetically acceptable regrowth, and another six (21.4%) had significant regrowth. No correlation was found between response and sex, age of onset of illness, extent, duration, or clinical type of disease. In 14 patients followed for a period ranging from 18 months to 8 years SADBE remained efficacious for relapses as well. This study demonstrates that SADBE is a valid and suitable treatment for children, particularly those who are resistant to conventional therapies.