Autoimmune neutropenias (AIN) in adults are a heterogeneous group of diseases with clinical manifestations varying from being asymptomatic to having infectious complications with considerable morbidity and mortality. They are characterized by autoantibodies directed against neutrophils, resulting in destruction of neutrophils. AIN can be divided into two forms. In primary AIN, neutropenia is usually the sole hematologic abnormality and it is more common in children. Secondary AIN, which is more prevalent in adults, is associated with underlying autoimmune diseases, malignancies, infections, particularly viral, neurological diseases or drug exposure. This article is an overview of these conditions with emphasis on secondary AIN; it also discusses the available serological methods for antibody detection and recent therapeutic developments including colony stimulating factors, rituximab and Campath-1H.