Background/aim: Polycythemia Vera (PV) is a myeloproliferative disorder characterized by overproduction of morphologically normal red blood cells (RBCs), granulocytes, and platelets, a phenotype that is caused by a mutation (V617F) in Janus kinase 2 (JAK2). However, JAK2 V617F is also found in approximately 50% of patients with essential thrombocytosis and primary myelofibrosis, rendering its presence nonspecific as a diagnostic test. An increased red cell mass is a major criterion for the diagnosis of PV according to World Health Organization (WHO) 2016 criteria. High hemoglobin (Hgb) or Hematocrit (Hct) are universally used as indicators of an increased red cell mass for the diagnosis of PV. However, conditions such as iron deficiency (ID) with decreased mean cell volume may mask the diagnosis due to nonelevated Hct level. The aim of this study was to investigate the clinical characteristics of the patients with unclassifiable non-CML classical myeloproliferative disease with microcytosis (MPD/M) and nonelevated Hgb and Hct levels at diagnosis and to determine if some of these cases could be real PV cases masked due to ID-related microcytosis.