OBJECTIVE: The studies about immunoglobulin A (IgA) deficiencyin the clinical, laboratorial and terapeutic aspects. METHODS: Bibliografic review of the last ten years about thesubject by Medline system and direct research. RESULTS AND CONCLUSIONS: IgA deficiency is the most frequent primary immunodeficiency, with the average prevalence of 1:700and must be studied in its clinical, laboratorial and terapeutic aspectsby pediatrician and other specialists. The clinical characteristics ofthe total and partial immunodeficiency must be known, so as thecomplications and laboratory techniques for determine accurate diagnosis and prognostic.