Background & Aims: The benefits of combined systemic and liver-directed treatments in inoperable intermediate- or advanced-stage hepatocellular carcinoma (HCC) have yet to be defined. This article presents the planned safety analyses for the first 40 patients randomized to radioembolization with yttrium-90 (90Y) resin microspheres followed by sorafenib (n = 20) or sorafenib only (n = 20) in the SORAMIC study. Methods: Patients identified for palliative treatment who were poor candidates for transarterial (chemo)embolization (including those failing TACE) with preserved liver function (Child-Pugh ≤B7) and ECOG performance status <2 were screened. Radioembolization was administered using a sequential lobar approach. On day 3 after the last radioembolization procedure, sorafenib 200 mg twice daily was initiated escalating to 400 mg twice daily 1 week later; a matching sorafenib dose schedule was initiated in the control arm. Results: Patients were followed up for a median of 8.3 months. Median total implanted activity of 90Y was 1.87 (range: 0.54-2.35) GBq. Patients received a similar intensity and duration of sorafenib in the combination-treatment arm (median daily dose 614 mg over 8.5 months) and control arm (557 mg over 9.6 months). The incidence of total (196 vs. 222) and grade ≥3 (43 vs. 47) adverse events was similar in combination-treatment arm and control arm respectively (P > 0.05). No significant differences in the number of total or grade 3/4 toxicities were recorded for: total bilirubin, albumin, liver enzymes, ascites, Child-Pugh, fatigue, hand-foot skin reaction, blood pressure or diarrhoea. Conclusions: Radioembolization followed by sorafenib appears to be as well tolerated as sorafenib alone.