Aim: Here in this study we are focusing on antibody titre level of different age groups, and discuss its importance in various clinical scenarios. Objectives: To find out the Anti A, Anti B titre levels in A, B and O blood group individuals, the pattern of titre level, and to look for any gender predominance and discuss clinical significance of antibody titre level in various aspects of transfusion. Method: The study were performed on a total of 300 blood samples received in Blood Bank at St. John's medical College Hospital, Bangalore for blood grouping and typing and donor samples received for cross matching. Samples were categorized into 4 groups.30 samples collected from the age group of 5 months to 1 year and 90 samples each collected from rest of following groups. 5-10 years, 20-25 years and 60-65 years. Result: In our study we concluded that the naturally occurring ABO antibodies begins to synthesize at the age of 5-6 months will reach its peak level by the age of 20-25 years and gradually decrease as the age advances. There is no significant difference in the levels of Anti A and Anti B levels of 'A' and 'B' group & Anti A, Anti B levels in 'O' group individuals. Titre levels of both the antibodies seem to show similar values in both the genders. Conclusion: Various transfusion requirements like, pregnancy, Incompatible transfusion due to unavailability of compatible group, plasma apheresis, plasma exchange, incompatible platelet transfusion, ABO incompatible organ transplantation require thorough monitoring of naturally occurring Antibodies, So we suggest that Compulsory antibody titration of all donors, especially O group donors (as they produce IgG type antibodies) should be done.