Two patients respectively with acute agranulocytosis and with chronic neutropenia were treated with high-dose immunoglobulins. In the first case, immunologic tests revealed the presence of antigranulocytic autoantibodies: all other tests (antinuclear antibodies, anti-DNA antibodies, immune complexes, latex) were negative. In the second case, all the above mentioned tests were negative. In both patients, neutrophil number returned to normal after the second immunoglobulin injection. Eight months after treatment, the neutrophil count was normal in the first patient and anti-granulocyte tests had become negative. In the second patient there was a late recurrence of neutropenia. The diagnosis of autoimmune neutropenia is difficult to confirm. In the case of peripheral "idiopathic" neutropenia, with infectious complications, high-dose immunoglobulin administration thus appears justified regardless of the results of the immunologic tests. This therapy also has the advantage of avoiding side effects of steroid treatment or of splenectomy.