Blood transfusion is an essential service in the healthcare system. Hence, effective quality systems are required to ensure consistent quality and the safety of blood transfusion. World Health Organization (WHO) has established the Quality Management Programme (QMP) for blood transfusion services, a global initiative to support Member States in ensuring the overall safety of the transfusion process, from the recruitment of blood donors to the transfusion of blood and blood products and follow-up of the recipients. External quality assessment (EQA) is an important, but very specific and specialized, part of the monitoring process. EQA schemes for blood transfusion safety focus primarily on blood group serology and testing for transfusion-transmissible infections. EQA is an external assessment of a laboratory’s performance in testing samples of known, but undisclosed, content and comparison with the performance of other laboratories. It is designed to raise standards of performance in blood transfusion services, reference centres, hospital blood banks and other laboratories undertaking blood group serology testing for diagnostic purposes.