Background: Blood transfusion safety is a major issue in transfusion medicine. Adverse transfusion reactions (ATRs) are necessary to identify to maintain blood transfusion safety. Our study aimed to determine the frequency and different type of ATRs in diabetes subjects reported in a tertiary hospital in Dhaka, Bangladesh. Materials and Methods: It was a retrospective cross-sectional study conducting in a tertiary care hospital in Dhaka in duration on June 2025 and December 2025. ATRs were evaluated by the blood transfusion officer and classified using standard definitions. Results: A total of 253 units of whole blood were transfused, 190 units transfused in diabetic subjects and 63 units in health subjects respectively. In total subjects 68% ATRs were found, involving allergic (17%), delayed hemolytic reactions and Transfusion-associated circulatory overload (TACO) (17%), Transfusion-Related Acute Lung Injury (TRALI) reaction (3%), bacterial contamination 7%, RBC destruction to foreign antigen (4%) and brady cardiac 3%) were noticed. Among 190 diabetic subjects, 68.4% ATRs were observed including 15.6% delayed Hemolytic reactions, 16.8% allergic reaction, 17.9% TACO, 3.2% TRALI reaction, 7.9% bacterial contamination, 4.7% RBC destruction to foreign antigen reaction and 2.1% brady cardiac reactions which were higher (p=ns) rate than health subjects. Conclusion: Our study concluded that 68% ATRs were noticed in total subject where as 68.4% ATRs noticed in diabetic subjects that carries high infection rate. Safe blood transfusion services may have decreased these ATRs issues.