An appropriate and adequate blood flow and oxygen delivery is paramount to free flap viability and success. The perioperative use of tranexamic acid (TXA) is associated with less risk for blood loss and blood transfusion in trauma, gynaecology, ear nose and throat (ENT) and orthopaedic surgery. As an antifibrinolytic drug, TXA has generally been avoided in microsurgery. The aim of this study is to evaluate the safety and benefit of using TXA in microsurgery.We performed a retrospective single centre cohort study at the Pyramid Clinic, Zurich, Switzerland, including 98 free tissue transfers for breast reconstruction from 2011 to 2013. According to the estimated blood loss, up to 3 g TXA were administered intravenously in 63 free flaps perioperatively.No thrombosis (0%) of micro-anastomosis and 5 haematomas (10.0%) occurred after administration of TXA. In the control group, 1 thrombosis (3.0%) of a flap-vein and 6 haematomas (18.2%) occurred. Blood loss was significant lower (P<0.001) after administration of TXA.In this study, administration of TXA did not increase thrombosis in free tissue transfer and showed a reduced haematoma rate and significant reduction of blood loss. TXA is supposed to be safe and a reasonable adjunct for patients with anaemia and a higher intraoperative or postoperative blood loss.