Aim of study: To identify and report various type of primary immunodeficiency disorders in children at Zagazig university hospitals, and their characteristic features, clinical manifestations and laboratory profiles. Patients and methods; patients with history,clinical findings and laboratory findings matching with any of eight classes of primary immunodeficiency were included in this study, also we used ten warning signs,immunodediciency disease related score in evaluation of patients. Results: Fifty patients were diagnosed with different primary immunodeficiency disorders in Pediatric department, Zagazig University Hospital during period from July 2011 to July 2013. The spectrum of PIDs in our center was as follow: predominantly antibody deficiency was the most common category (46%) followed by combined immunodeficiency (22%) then well defined syndromes (20%), auto inflammatory disorders (8%), complement disorders (4%). No cases were diagnosed in any category of phagocytic disorders, innate immunity or immune dysregulation. Selective IgA deficiency was the most frequent disease type. Median age of onset of symptoms was 7 months, the median age of diagnosis lag was 24 months.Pneumonia was the most common presentation. Consanguinity rate was 60%. Mortality rate was 20% mostly duo to bronchopneumonia. Conclusion: primary immunodeficiency disorders are not rare in our center ,but under diagnosed.