Idiopathic hypereosinophilic syndrome (IHS) is reported in a 59-year-old farmer. Skin manifestations were represented by pruritic erythemato-squamous and papulonodular lesions, the heart was affected by endomyocardic fibrosis, and periodic intestinal colics denoted a possible gut involvement. A mild and transient beneficial effect was achieved by treatment with antihistamines, sodium-chromoglycate, steroids. Recent studies indicate that IHS hypereosinophilia is caused by interleukins 3 and 5, cytokines able to activate circulating eosinophils and to enhance the survival of these cells.