Blood genetic markers were investigated in a sample of 111 Bedouin and 412 non-Bedouin male Arabs of Jordan. The frequencies of the ABO alleles were similar in these two groups, with a relatively high frequency of the·gene (0.63; 0.61). The frequencies of Rh genes were slightly different in these two groups, with a higher Ro, and a lower r in the Bedouins. A sub-sample of a smaller size was investigated for the distribution of haptoglobin types, Tf subtypes and red-cell G6PD (glucose 6-phosphate dehydrogenase) phenotypes. There was no significant difference in any of the systems between the two populations. No haemoglobin variant was detected. The study confirms the Arab characteristics of Jordanians with a small degree of African admixture