The Wiskott-Aldrich syndrome is a primary immunodeficiency characterized by congenital microthrombocytopenia, eczema and recurrent infections. This paper reports the case of a 3-year-6-month male patient, whose maternal uncle died at the age of 3 months due to fulminant sepsis from a pulmonary infection. The patient was a product of the first pregnancy, he was born at 27 weeks' gestation and weighed 1,400 g. As a neonate he was hospitalized during the first 2 months of life because of a low gastrointestinal bleeding, thrombocytopenia and severe infections. In the next 4 months and before coming to our hospital the infant was hospitalized 54 times. On admission he presented disseminated dermatosis, enlarged neck lymph nodes and psychomotor retardation. Laboratory studies revealed hemoglobin 8.1 g/dL, platelets 31,000/uL, mean platelet volume 5.6 fL, IgM 39.3 mg/dL, IgA 67 mg/dL, IgG 1,380 mg/dL. On several occasions he received globular packages and platelet concentrates. The infusion of immunoglobulin G was started every 21 days. Bone marrow transplantation was delayed due to the complications that merited 13 hospitalizations and severe thrombocytopenia, low gastrointestinal bleeding, septic arthritis, infectious gastroenteritis, chronic suppurative otitis media and severe folliculitis. At the age of 4 years BMT of cord was performed, and 26 days after transplantation he presented septic shock and died. The prognosis of bone marrow transplantation in Wiskott-Aldrich syndrome and in other primary immunodeficiencies depends on the promptness of its performance at early stages in life. It is important that the first contact physicians be aware of the primary immunodeficiency signs and symptoms.