Dr. Karen Montenegro Flores, a specialist in Clinical Hematology and Hemotherapy from Fluminense Federal University (Brazil), with postgraduate studies in Flow Cytometry and Hematopoietic Stem Cell Transplantation (Spain, Mexico, and Brazil), presented an introduction to hematology in the clinical laboratory. She covered the fundamentals and applications of the complete blood count, techniques and tools for cell counting, and the use of hematoscopy as a method for visualizing and studying blood cells. She also explained hemoglobin measurement methods and their importance in diagnosis. Dr. Flores discussed quality control in hematology, shared practical cases involving blood counts in various international contexts, and highlighted protocols, recent advances, as well as key challenges and solutions in the management of hematology laboratories across different countries.