Background: Modified radical mastectomy (MRM) is one of the surgical procedures for breast cancer management. Many complications are associated with wound healing, like hematoma, dehiscence, infection, chronic seroma and skin necrosis. The objective of this study was to compare the mean blood loss in drain output of topical versus intravenous tranexamic acid (TXA) use among patients undergoing modified radical mastectomy.Methods: This randomized controlled trial was conducted at department of surgery, Holy Family hospital, Rawalpindi from November 2019 to November 2020. 130 patients were randomly divided into two groups. Group A patients received tranexamic acid topically while group B patients received intravenous tranexamic acid during modified radical mastectomy. Drain output and blood loss was recorded after twenty-four hours of the surgery.Results: Mean age was 51.15±10.33 in group A, while it was 50.58±10.59 in group B. Mean duration of breast cancer among the patients was 11.45±8.70 months. Mean blood loss, 24 hours after MRM was 40.68±20.79 ml in the topical group, while it was 50.83±26.38 ml in the intravenous group (p=0.016).Conclusions: Topical tranexamic acid showed significantly better control on blood loss as compared to intravenous TXA.