There is currently no consensus on the most suitable treatment for the recurrence of hepatocellular carcinoma (HCC) after liver transplantation. This open, multicenter, retrospective, uncontrolled cohort study was designed to evaluate the safety and preliminary efficacy of the combined use of a mammalian target of rapamycin (mTOR) inhibitor and sorafenib in this setting. In 31 patients who suffered from HCC recurrence after liver transplantation, the immunosuppressive therapy was changed to mTOR inhibitors, and systemic treatment with sorafenib was initiated. This combination was maintained until symptomatic tumor progression, death, hepatic decompensation, or unacceptable toxicity occurred. Primary treatment efficacy was determined by overall survival and progression-free survival, and secondary efficacy was determined by the overall response rate. Toxicity parameters associated with the use of sorafenib and mTOR inhibitors were also analyzed. The overall response rate according to the Response Evaluation Criteria in Solid Tumors was 3.8% (1/26), and there was sustained stabilization of the disease in 13 additional cases (50.0%). The median overall survival was 19.3 months [95% confidence interval (CI) = 13.4–25.1 months], and the median time to progression was 6.77 months (95% CI = 2.3–11.1 months). Only 2 grade 3/4 cases of hyperglycemia and 1 case of grade 3/4 mucositis were reported, and they were possibly related to mTOR inhibitors. The most common severe adverse event probably related to sorafenib was diarrhea (12.9%). In conclusion, the coadministration of sorafenib and an mTOR inhibitor could be effective despite notable toxicity in patients with post–liver transplant HCC recurrence not suitable for radical therapy. The toxicity and efficacy need to be further evaluated in randomized controlled studies for this combination to be considered a valid option. Liver Transpl 18:45–52, 2012. © 2011 AASLD.