This review summarizes recent literature regarding the clinical and molecular features of nonmalignant leukocyte disorders in children. Leukocyte adhesion deficiency and chronic granulomatous disease, two inherited disorders of neutrophil function, continue to be the best-characterized disorders with respect to specific molecular defects. The underlying causes of severe congenital neutropenia and cyclic neutropenia remain elusive. Clinical features of immune-mediated neutropenias and their differential diagnoses are also reviewed.