The aim of this retrospective trial was to analyze the value of preoperative (18)F-fluoro-deoxyglucose positron emission tomography ((18)F-FDG PET) to predict parameters of tumor aggressiveness among liver transplant (OLT) patients with hepatocellular carcinoma (HCC). Fifty-five patients with HCC underwent (18)F-FDG-PET during evaluation for OLT. Nineteen patients demonstrated increased (18)F-FDG uptake on PET pre-OLT (PET(+)), and 36 patients revealed negative PET findings (PET(-)). PET(+) patients showed a relative risk of 9.5 and 6.4 for poor differentiation and for microvascular invasion (MVI) in the HCC at explant pathology, respectively. Of the 10 patients (18.2%) who developed HCC recurrences, 9 (90%) revealed increased (18)F-FDG uptake pre-OLT; only 1 (10%) showed a PET(-) status (P < .001). Apart from poor tumor differentiation, PET(+) status was identified as an independent predictor of tumor recurrence post-OLT (odds ratio, 23.9). Our study demonstrated that (18)F-FDG uptake on PET is a reliable preoperative predictor of tumor recurrence after OLT in patients with HCC, triggered by its high association with poor tumor differentiation and MVI.