The aim of this study was to determine the frequencies of ABO Blood groups and haemolysins
(? and ß) in Osogbo metropolis. Seventeen thousands, nine hundred and thirty one subjects
(Age?18) who consented to donating blood for transfusion and/or blood group determination
were included in this study. About 5mls of blood were collected into plain bottles from each
subject. Cells and sera grouping were subsequently carried out after clot retraction. Blood
group O individuals have the highest frequency (53.6%) followed by B and A with 21.3% and
21.1% respectively. Blood Group AB individuals recorded the lowest frequency of 4.0%. ? and
ß haemolysins were discovered in 4 out of 9,605 blood group O subjects (0.042%)
concurrently. All blood transfusion/-banking centers in the community should always strive
to stock blood units and products in this proportion to be able to respond to transfusion needs
of the community adequately and appropriately too. Screening of blood units for clinically
significant antibodies including ? and ? haemolysins is recommended to be religiously
observed, while selection for cross matching should be based on the information generated
from both blood grouping and antibody screening. Homologous transfusion should remain the
priority.