The authors report 25 cases of allergy to animal hair in childhood. 13 patients were polisensitized, and in the remaining 12 hair was the only allergen responsible for the clinical picture. The main clinical features are discussed and the high incidence of atopic cutaneous signs pointed out. In three patients these were the only clinical manifestation. Desensitization was successful, although this is, difficult to undertake without a substantial modification of the surrounding environment.