Background: Allergic transfusion reactions (ATRs) are common adverse events during blood transfusions, ranging from mild urticaria to severe anaphylactic shock. Elevated serum immunoglobulin E (IgE) levels are known to mediate these reactions. This study aimed to assess the relationship between serum IgE levels and the Presence of ATRs in patients receiving fresh frozen plasma (FFP) transfusions. Methods: A cross-sectional observational study was conducted at the Department of Transfusion Medicine, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh, from March 2019 to August 2021. The study included 55 patients aged 5-60 years who received FFP transfusions. Demographic data, clinical symptoms, and IgE levels were recorded. Data were analyzed using SPSS version 26, with statistical significance set at p<0.05. Result: The majority of participants were males (94.55%) and aged 11-20 years (45.45%). Most patients (85.45%) received multiple units of FFP. Clinical symptoms included itching (56.36%), urticarial rash (29.09%), vomiting (7.27%), and hypotension (7.27%). Raised IgE levels were found in 52.73% of participants, and a significant association was observed between elevated IgE levels and the presence of allergic reactions (p<0.01). Patients with allergic reactions had significantly higher mean IgE levels (521.4±434.6 IU/mL) compared to those without allergic reactions (67.8±33.2 IU/mL). Conclusion: Elevated serum IgE levels are significantly associated with the Presence of ATRs in patients receiving FFP transfusions. Monitoring IgE levels can help predict and manage allergic reactions, thereby improving transfusion safety and patient outcomes.