BACKGROUND: Immune checkpoint inhibitors and chemotherapy can synergistically increase efficacy in a variety of malignancies. We conducted this phase Ib/II study to assess the safety and efficacy of anti-PD-1 antibody camrelizumab in combination with FOLFOX4 for treatment-naive advanced hepatocellular carcinoma (aHCC). METHODS: This open-label, multicenter phase Ib/II study (NCT03092895) enrolled patients with aHCC and without prior systemic treatment for treatment with camrelizumab (3 mg/kg) and FOLFOX4 every two weeks. First, six patients were enrolled, followed by an additional 28 patients after dose-limiting toxicity cases were determined to be <33% of patients. The primary endpoint was tolerability and safety of treatment. RESULTS: A total of 34 aHCC patients were enrolled and received study treatment. No dose-limiting toxicity were observed in the first six patients enrolled. Twenty-nine (85.3%) of the total 34 patients had grade ≥3 treatment-related adverse events (TRAEs), with the most common ones being decreased neutrophil count (55.9%) and decreased white blood cell count (38.2%). No TRAEs-related deaths occurred. The objective response and disease control rate were 29.4% (95% CI, 15.1-47.5) and 79.4% (95% CI, 62.1-91.3), respectively. The median duration of response, progression-free survival, and overall survival was 6.9 months (range, 3.3-11.5), 7.4 months (95% CI, 3.9-9.2), and 11.7 months (95% CI, 8.2-22.0), respectively. CONCLUSION: Camrelizumab combined with FOLFOX4 for first-line treatment of patients with aHCC showed good safety and tolerability, with promising preliminary antitumor activity.