Living donor liver transplantation (LDLT) is becoming a widespread procedure. However, the risk of surgical and medical complications in healthy donors is still a major concern. Hypercoagulability contributes to thromboembolic complications after surgery, but alterations of hemostasis after liver resection are difficult to predict. This study aims to define the perioperative coagulation profile of living liver donors by the use of both routine tests and thromboelastogram (TEG). Ten subjects undergoing right hepatectomy for LDLT were studied. A complete coagulation screening was performed before operation. The coagulation profile was evaluated by platelet count, prothrombin time-international normalized ratio (PT-INR), activated partial thromboplastin time (aPTT), and TEG at the beginning and at the end of surgery, and on days 1, 3, 5, and 10 after operation, while the donors were under low molecular weight heparin (LMWH) prophylaxis. At preoperative screening, no subject showed evidence of a prothrombotic state. In all cases, TEG was normal at the beginning of surgery. In the postoperative period, despite decreased platelet counts, increased PT-INR, and normal aPTT values, TEG evidenced the progressive development of hypercoagulability in 4 subjects on day 5 and in 6 subjects on day 10. One donor with a definitely hypercoagulable TEG on day 5 experienced deep venous thrombosis (DVT) on day 8, which was resolved with therapeutic doses of LMWH. In conclusion, despite routine tests suggesting hypocoagulability and LMWH prophylaxis, TEG monitoring showed the unexpected occurrence of hypercoagulability in the majority of the subjects after hepatectomy for LDLT. TEG monitoring could be useful in the perioperative management of donors to guide antithrombotic treatment and increase the safety of the procedure. (Liver