The nucleus as the main storage of genetic information is comprised of compartments, among which the nucleolus is the best-studied and the most prominent one. The nucleolus is not surrounded with a membrane but is formed around rDNA regions on acrocentric chromosomes. Consequently, its function - the upgrading and transcription of rRNAs by RNA polymerase I - results in the formation of ribosomal subunits. Given the function, the nucleolus can be divided into three morphological regions, namely fibrillar center (FC), dense fibrillar component (DFC) and granular components (GC). Apart from its primary function in ribosome biogenesis, it has additional roles in other physiological processes. In this work we analysed the nucleoli of the primary megakaryocytes. More specifically, the relationship between the megakaryocyte surface, the number of lobulus nuclei, and the number of nucleoli was evaluated. Results show that with maturation of megakaryocytes the number of nucleoli increases, while in the most mature cells nucleoli are not visible. Since megakaryocytes are rare bone marrow cells and represent highly specialized platelet precursors, additional information on nuclei and nucleolus in megakaryocytes may be useful in further studies of various diseases affecting megakaryocytes and therefore platelets.