Wiskott-Aldrich syndrome is a rare, hereditary disease occurring in males and was first described in 1937. It is characterized by cutaneous eczema, thrombocytopenic purpura and an increased susceptibility to infection due to an immunologic defect. Patients with Wiskott-Aldrich syndrome have a poor antibody response to polysaccharide antigens, low levels of IgM and high levels of IgA and IgE in serum. Oral manifestations of Wiskott-Aldrich syndrome was observed a spontaneous gingival bleeding, palatal petechiae, ulcer and gingival hyperplasia. We report on dental treatment of a 5 years old boy with severe spontaneous gingival bleeding and ulcer suffered from Wiskott-Aldrich syndrome. Prophylactic antibiotics to prevent infection and all potential measures including platelet concentrate therapy to prevent postoperative bleeding should be undertaken. Good oral hygiene should be maintained for prevention of infection by oral normal flora.