Reticulocytes are young erythrocytes, cells without a nucleus and with remnants of ribonucleic acid in their cytoplasm. They develop in the bone marrow from acidophilic erythroblasts. The number of reticulocytes is an important laboratory parameter in assessing the erythropoietic activity of the bone marrow in response to anemia, bleeding, chemotherapy, and various toxins. The gold standard for counting reticulocytes is light microscopy, which is time-consuming and tedious, prone to errors due to variability and subjectivity among observers. With the advancement of technology, digital analyzers for cell morphology have been developed, enabling faster examination of peripheral blood smears. The aim of this thesis is to compare the results of reticulocyte counting using the manual method with light microscopy, the automated method on the Sysmex XN-10 hematology analyzer, and the counting within the erythrocyte submenu on the Sysmex DI-60 cell morphology analyzer, and to determine if it is suitable for reticulocyte counting. To assess the comparability of the methods, Spearman's rank correlation coefficient (ρ), Passing- Bablok regression, and Bland-Altman analysis were used. A very high correlation was found between the Sysmex DI-60 and the automated Sysmex XN-10 (ρ = 0,970) method and the manual method (ρ = 0,970), indicating a very good concordance of the methods. A small, expected deviation was found between the Sysmex DI-60 method and the manual method, as well as the Sysmex XN-10 method. It was concluded that the analyzer can be introduced into the routine work of the hematology laboratory for reticulocyte counting within the erythrocyte submenu.