Myelofibrosis (MF) is characterized by reticulin fibrosis of the bone marrow. It may occur in neoplastic disorders such as myelofibrosis with myeloid metaplasia (MMM) or other neoplasms involving the bone marrow. However, autoimmune phenomena have been described in patients with MF defining a distinct clinicopathological entity called autoimmune myelofibrosis (AIMF). We report two cases of AIMF and review the literature.