Research Paper (postgraduate) from the year 2009 in the subject Health - Public Health, ( Atlantic International University ), language: English, abstract: A total of 750 blood samples were collected into the dipotassium ethylene diaminetetra aceticacid (EDTA) tubes and BD vacutainer tubes from the population of Porto Novo at random rangingfrom 2 years to 70 years of age. The ABO blood group systems were tested on the samples by theforward and reverse technique of blood grouping by tube method.A total of 320 individuals were shown to be blood group O (43%), the blood group A were shownto be 226 individuals (30%), blood group B were 167 people (22%) and blood AB finally were 37people making up to 5% of the population tested. This work follows almost the same discoverymade by other researchers of ABO grouping system and did not show a significant differencesamong the groups except in that reported on Brazilian Indians in Mato Grosso which registered100% blood group O among Indians of Mato Grosso by Bier at al(1982).The work serves as a fundamental screening on the distribution of ABO blood group system inPorto Novo and did not indicate whether there exists a difference of ABO blood group systemdistribution among other islands of Cape Verde and also a reference point for those engaged inclinical blood use like the red cross organisation and paramedical units who at times give blood onemergency basis.