Background: A wide knowledge about the distribution of blood grouping in any population will help in the successful management of the blood banks. Aim: This study was conducted to find the distribution of ABO blood grouping and Rh typing in a tertiary care hospital in South India and to compare it with previous literature from India and other parts of the globe. Materials and Methods: This was a retrospective study done at the blood bank of a tertiary care hospital for a period of 5 years and 6 months ( January 2012 to June 2016). Forward blood grouping (Cell grouping) was done by both slide and tube agglutination method and Reverse grouping (Serum grouping) by tube agglutination method using daily freshly prepared known pooled A, B and O cells. Rh typing was done using antiglobulin technique. The results were recorded, analysed, tabulated and compared with previous similar studies. Results: Amongst the 9992 donors, O blood group formed the most common one - 3618 numbers (36.2%), followed by B blood group -3328 (33.3%) and A blood group - 2305 numbers (23.06%). AB was the least common blood group with 739 numbers (7.39%). 2 numbers (0.02%) of the rare Bombay blood group was present during the study period. In the Rh typing, majority, 9074 (90.8%) were Rh positive and only 918 (9.2%) were Rh negative. Conclusion: Regional blood group studies will provide a wide knowledge about the distribution of blood grouping in the population and will help in the successful management of the blood banks. A knowledge about the distribution of blood groups may also be useful to take preventive measures against certain diseases which have possible relationship with specific ABO groups.

Keywords: ABO Grouping; RH Typing; Blood Groups; Blood Bank; Transfusion.