Hematology has experienced significant growth in knowledge and insights over the past decade. This applies both to the physiology and pathology of cellular systems on a molecular basis, as well as to the identification and description of clinical syndromes and defined disease patterns. The study of cell kinetics has greatly contributed to the understanding of regulatory processes. Undoubtedly, the most exciting developments have occurred in the area of lymphocytes and granulocytes, revealing previously unknown functions and functional defects. Erythrocytes have also disclosed further secrets, particularly regarding the membrane, enzymes, and hemoglobin, as well as their rheological properties. Hemostasis has significantly improved diagnostic methods and expanded therapeutic options in several areas.