Wiskott-Aldrich syndrome is a rare inheritable disease. Though there are many reported cases in the world, there are only 3 reported cases in Korea. We experienced a 7 years old boy with Wiskott-Aldrich syndrome. The initial presentation was generalized petechiae due to thrombocytopenia. We diagnosed him to have idiopathic thrombocytopenic purpura and followed up him for several years. During follow-up the patient have been suffered from croup, perianal abscess, bronchitis, and otitis media. One year ago, inguinal mass developed and 3 months ago, cervical and axillary masses developed. The fine needle aspiration cytology and biopsy revealed angioimmunoblastic lymphadenopathy like atypical lymphoproliferative disorders associated with congenital immune deficiency. So we diagonsed the patient to have Wiskott-Aldrich syndrome through his clinical course and laboratory findings including eczema, persistent low platelet counts, low mean platelet volume, monoclonal gammopathy on serum electrophoresis and biopsy finding.