BACKGROUND & AIMS: The efficacy of fresh frozen plasma (FFP) transfusion in enhancing thrombin generation in patients with cirrhosis and impaired conventional coagulation tests has not been sufficiently explored. Thus, we aimed to assess the effect of FFP transfusion on thrombin generation in these patients. METHODS: Fifty-three consecutive patients receiving a standard dose of FFP to treat bleeding and/or before invasive procedures - if international normalized ratio (INR)/prothrombin time (PT) ratio were ≥1.5 - were prospectively enrolled. The primary endpoint was the amelioration of endogenous thrombin potential (ETP) with thrombomodulin (ETP-TM) after transfusion, which corresponds to the total amount of generated thrombin. INR/PT ratio and activated partial thromboplastin time (aPTT) were also assessed before and after transfusion. RESULTS: FFP enhanced ETP-TM by 5.7%, from 973 (731-1,258) to 1,028 (885-1,343 nM × min; p = 0.019). Before transfusion, evidence of normal or high ETP-TM was found in 94% of patients, even in those with bacterial infections. Only 1 (1.9%) patient had ETP-TM values reverting to the normal range after transfusion. Notably, no patients with low ETP-TM had bleeding. The median decrease in ETP-TM was 8.3% and the mean was 12.8% in 18 (34%) patients after transfusion (from 1,225 [1,071-1,537] to 1,124 [812-1,370] nM × min; p ≤0.0001). Similar responses to FFP transfusion were observed in patients with compensated and acute decompensated cirrhosis, acute-on-chronic liver failure, infection or shock. FFP significantly ameliorated INR and aPTT values (p <0.0001), but in a minority of patients the values were reduced to less than the cut-off point of 1.5. CONCLUSIONS: FFP transfusion enhanced thrombin generation and ameliorated conventional coagulation tests to normal values in a limited number of patients, and slightly decreased thrombin generation in 34% of cases. LAY SUMMARY: Transfusion of fresh frozen plasma in patients with cirrhosis only slightly improves coagulation test values in a limited number of patients and even appears to worsen them in a third of cases. Transfusion for the purpose of preventing or treating bleeding events could cause inherent risks and costs without clear benefits.