Asperger's syndrome is a subgroup of autism characterized by social deficits without language delay, and high cognitive performance. The biological nature of autism is still unknown but there are controversial evidence associating an immune imbalance and autism. Clinical findings, including atopic family history, serum IgE levels as well as cutaneous tests showed that incidence of atopy was higher in the Asperger group compared to the healthy controls. These findings suggest that atopy is frequent in this subgroup of autism implying that allergic inflammation might be an important feature in Asperger syndrome.