Severe post-transplantation thrombocytopenia (platelet count \<30×10⁹/L) occurs frequently after liver transplantation (LT) and is associated with increased bleeding risk, allograft dysfunction, and transfusion-related complications. Avatrombopag, an oral thrombopoietin receptor agonist, is approved for thrombocytopenia in chronic liver disease but its role in the post-LT setting remains unclear. This retrospective cohort study included adult LT recipients who developed severe post-transplantation thrombocytopenia (SPT) between November 2019 and August 2025. After 1:1 propensity score matching (nearest neighbor, caliper = 0.2 SD of the logit of the propensity score) for age, sex, etiology of liver disease, cold ischemia time (CIT), intraoperative blood loss (IBL), preoperative platelet count, and Model for End-stage Liver Disease (MELD) score, 67 patients who received avatrombopag (20 mg/day for 5 days) were compared with 67 matched controls who received standard care. The primary outcome was platelet rise rate (×10⁹/L/day). Secondary outcomes included absolute platelet increase, blood product utilization, concomitant thrombopoietic agent use, and 30-day complications (thrombosis, infection, mechanical ventilation, renal replacement therapy, death).