Introduction: The ABO blood group system was the first human blood group system discovered by Austrian scientist Karl Landsteiner in 1901. The ABO blood group system is divided into four blood types on the basis of presence or absence of A and B surface antigens A and B antibodies presence in the plasma. Positive and Negative of the blood group determines by presence or absence of the D antigen.. Objectives: This study was carried out to determine the distribution pattern of blood groups among blood donors at a tertiary care hospital of Puducherry Materials and Methods: It is a retrospective study done a period of 5 years from May 2017 to May 2022 that includes the 9062 blood donors. Blood group done as per the standard operative procedure. Data on the ABO and Rh blood group type of all blood donors was collected and analysed. Result: The most common ABO blood group type was Group O (38%) followed by group B (33.5%), group A (21.6%) and group AB (6.9%) and one Bombay blood group. The distribution of Rh(D) blood group type revealed 92.5% as Rh-positive and 7.5% as Rh-negative. Conclusion: The most common ABO blood group type in our region (Puducherry) is Group O followed by B and A while, AB and Bombay groups are the least common type. Knowledge of the blood group distribution pattern is essential for the effective delivery of blood banking services.

The authors have declared no competing interest.

Nil

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

PIMS Institute Ethics Committee(IEC) gave approval for this work.(REF NO: IEC: RC/18/107)

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present study are available upon reasonable request to the authors