Orthotopic liver transplantation (OLT) is the only curative therapy of HCC with underlying cirrhosis, but due to HCC metastasis and recurrence, its benefit is limited to a small population who meet the strict selection criteria. We previously reported that Licartin ([ 131 I]mAb HAb18G/CD147) was safe and effective in treating HCC patients, and its antigen, HAb18G/ CD147, was closely related to HCC invasion and metastasis. Here, we reported a randomized controlled trial to assess the post-OLT antirecurrence efficacy of Licartin in advanced HCC patients. We randomized 60 post-OLT patients with HCC, who were at tumor stage 3/4 and outside the Milan criteria before OLT, into 2 groups. Three weeks after OLT, the treatment group received 15.4 MBq/kg of Licartin, while the control group received placebo intravenously for 3 times with an interval of 28 days. At 1-year follow-up, the recurrence rate significantly decreased by 30.4% (P ϭ 0.0174) and the survival rate increased by 20.6% (P ϭ 0.0289) in the treatment group, compared with those in the control group. For the control group versus the treatment group, the hazard ratio for recurrence was 3.60 (95% confidence interval [CI], 1.50-8.60) and that for death was 3.87 (95% CI, 1.23-12.21). Licartin treatment also resulted in an earlier decreased AFP level and a longer time of normal AFP level than placebo (P ϭ 0.0016). No Licartin-related toxic effects were observed. Conclusion: Licartin is a promising drug for preventing post-OLT tumor recurrence in advanced HCC patients excluded by the currently strict criteria for OLT. HAb18G/CD147 can be a good drug target.