Bruton's agammaglobulinemia is a primary immunodeficiency with a disease onset during the first months of age, when the maternal serum immunoglobulin levels decrease. It is characterized by recurrent infections and agammaglobulinemia. We report the case of a 6-year-old male patient with third-degree consanguinity, product of a third pregnancy and complete immunization scheme. He had a history of oral candidiasis at the age of 3 months, chicken pox at the age of 7 months, and two episodes of complicated bronchopneumonia at the age of 1 year and 6 years. He was admitted to the hospital because of fever and cough. Examination of the chest showed rales and right basilar hypoventilation, and a blood cell count revealed leukocytosis and neutrophilia. The diagnosis of pneumonia was made. He was treated with IV antibiotics. Serum immunoglobulins were reported to be low (IgM 55 mg/dL, IgA 0.9 mg/dL, and IgG 199 mg/dL). With these findings the clinical diagnosis of X-linked agammaglobulinemia (ALX) was concluded. A molecular test was performed fining a BTK gene confirming the diagnosis of Bruton's disease. Therapy with intravenous IgG was started every 21 days. During his evolution, he presented three episodes of rhinosinusitis, one of suppurative otitis media, and four events of pneumonia that required 37 days of hospitalization. After hospital discharge, the patient was free of infections and he returned to his daily activities. In cases of recurrent and severe respiratory infections in children, we must consider primary immunodeficiency disease in the differential diagnosis, mainly antibiotic deficiency. Early diagnosis and treatment improves the survival and quality of life in these patients.