This study aimed to assess the prevalence, severity, and etiology of neutropenia in infants and children admitted to a children's hospital in Egypt. A total of 200 patients with neutropenia were recruited from April 1, 2010 to September 30, 2010. Patients with a known hematological or immunological disease were excluded. Patients were followed till recovery or an underlying cause was uncovered. Viral serological analysis was done for patients with moderate/severe neutropenia, including cytomegalovirus (CMV); Epstein-Barr virus (EBV); hepatitis A, B, and C viruses; and HIV. Antineutrophil cytoplasmic antibody (ANCA) tested by enzyme immunoassay and bone marrow aspirate were done for prolonged neutropenia. The results revealed that neutropenia was mild in 90 (45%), moderate in 56 (28%), and severe in 54 (27%). Clinical diagnosis at admission was bronchopneumonia (38%), pyrexia of undetermined etiology (17%), bronchiolitis (13%), urinary tract infection (9%), acute gastroenteritis (8%), hepatitis (6.5%), and septicemia (5%). Patients with mild neutropenia recovered within 1 week. Among 110 patients with moderate/severe neutropenia, 80 (73%) recovered in <3 weeks. Predictors of prolonged neutropenia were age younger than 18 months (P < .01), absolute neutrophils count (ANC) < 500/mm(3) (P < .05), hemoglobin < 10 gm/dL (P < .05), and positive CMV serology (P < .01). CMV and EBV serology were positive in 34.5% and 7.3% of patients, respectively. ANCA was positive in 42.8% of patients with prolonged severe neutropenia. In conclusion, neutropenia is a frequent finding in Egyptian infants and children, usually mild and transient, and mainly associated with infection. CMV and EBV are associated with prolonged neutropenia. Immune neutropenia is a common cause of moderate/severe neutropenia in the first two years of life.