At present, none of the methods published to date can detect all variant alleles in all ethnic groups. It has become increasingly obvious that there is a considerable risk for false phenotype predictions if the DNA-based methods have not been investigated with samples of known phenotypes before introduction into the clinical laboratory. Obvious as this may seem, numerous examples of discrepancies or erroneous phenotype predictions have been reported and discussed in the scientific literature over the last few years [4]. Several studies have revealed major differences in individuals of African, Amerindian and Asian ethnic origin, especially in the complex ABO [5] and RH [6,7] blood group systems. There is limited data concerning the distribution of blood groups in Arabian populations, and even less information is available concerning the correlation between blood group phenotype and genotype. The purpose of this study was to evaluate selected genotyping methods in current use at our facility for phenotype prediction of clinically significant blood group systems (Table 1) in a cohort of Jordanian blood donors, representing a population group not previously investiga