OBJECTIVE: The paper aims to describe the phyisiology of iron, bone marrow aspiration and cytochemical reaction for the detection of iron using Prussian/Berlin blue stain. Moreover, the aim is to show the morphological features of dyserythropoiesis in myelodysplastic syndrome, ring sideroblasts, which are the result of abnormal cellular iron metabolism. The aim is also to show a cytologic evaluation of bone marrow in iron deficiency anemia and anemia of chronic disease. MATERIALS AND METHODS: The literature was searched by the topic and research subject, authors and journals. The targeted search was conducted using MEDLINE/PubMed databases, Science Direct, Google Search and scientific papers. The literature review covers the period up to 2019 and relies on publicly available databases. In analysing the relevant articles, the most important results, discussions and conclusions were singled out and presented in this final paper. RESULTS: Cytological analysis of bone marrow aspirates is crucial in patients with various hematopoietic and nonhematopoietic diseases. Staining of bone marrow aspirates with MGG method is suitable for standard cytomorphological analysis, while cytochemistry and immunocytochemistry can be done on additional smears. A part of aspirate, if indicated, is used for immunophenotyping, cytogenetic and molecular analyses. The examination of bone marrow smear stained with Prussian/Berlin blue can semiquantitatively estimate the storage of iron in the body. In iron deficiency anemia, sideropenic anemia, staining bone marrow aspirate with Prussian/Berlin blue reveals a total lack of iron granules in erythroblasts and bone marrow particles. Functional iron deficiency in anemia of chronic disease occurs in chronic inflammatory conditions in which iron is retained in the cells of the macrophage histiocyte system of bone marrow. Sideroblastic anemia occurs as a result of an acquired disorder or reduced heme synthesis in erythroid precursor cells, where iron is accumulated in ring sideroblasts. CONCLUSION: The analysis of bone marrow aspirates stained with Prussian/Berlin blue is an important method not only in assessing higher or lower iron stores but also in showing red cell precursors with an abnormal distribution of iron in the cytoplasm.