This "Practical Guide to ABO and Rhesus Blood Grouping" is intended primarily for public health biologists, physicians and laboratory technicians.The reading of this guide should enable interested persons to better understand the ABO, Rhesus blood grouping validation process and to manage discrepancies encountered during ABO, Rhesus blood grouping thanks to the practical solutions proposed in this guide.No use of this guide is permitted without the author's permission.