The ABO and Rhesus blood group series is the commonest and most important blood group series. In order to determine its distribution among the indigenes of Ijaw ethnic group in Niger Delta Region, Nigeria, a retrospective study of records of blood groupings from 1046 subjects comprising blood donors, blood recipients, patients attending routine antenatal care as well as individuals who presented for routine medical examinations, over a five year period (2005-2009), was done. Overall, blood group O (65.30%) was the highest, followed by blood group B (19.03%), and blood group A (13.57%) while blood group AB (2.10%), was the least. For the Rh (D) distribution, 95.70% were Rhpositive while 4.30% were Rh-negative. The distributions, according to gender, as well as according to site of study, follow the same trend as that of the general studied population. The results from this study will be useful to health planners and service providers.

KEY WORDS: Blood group, Ijaw, Ethnic, Nigeria.