Purpose <p>Although immune checkpoint inhibitors combined with chemotherapy improve survival in advanced gastric cancer (AGC), comparative evidence across first-line regimens remains insufficient. This study aimed to systematically evaluate their relative efficacy and safety.</p> Methods <p>PubMed, Embase, the Cochrane Library, Web of Science, and major conferences were searched up to February 28, 2025. Eligible RCTs comparing ICI-related regimens as first-line AGC treatment were included. Primary outcomes were overall survival (OS) and progression-free survival (PFS).</p> Results <p>Eleven RCTs involving 8,999 patients, six integrated strategies, and twelve specific regimens were included. Dual-target ICI-chemo and single ICI-chemo showed significant survival benefits over chemotherapy, whereas dual ICIs±chemo and single ICI alone did not. Dual-target ICI-chemo was associated with significantly better survival than both dual ICIs±chemo and single ICI±chemo. Among the specific regimens, cadon-chemo achieved the most favorable OS and PFS. No significant OS differences were observed among the single ICI-chemo regimens. In PD-L1-positive subgroups, both dual-target ICI-chemo and single ICI-chemo significantly improved survival compared with chemotherapy, with cadon-chemo being most effective in CPS ≥ 10 and CPS ≥ 1, and SHR1701-chemo in CPS ≥ 5. In the CPS &lt; 5 subgroup, dual-target ICI-chemo significantly improved OS, while single ICI-chemo showed a trend toward benefit. However, no ICI-based strategy demonstrated benefit in CPS &lt; 1.</p> Conclusions <p>Dual-target ICI-chemo appears to be the most effective first-line strategy for AGC based on current indirect evidence, surpassing single ICI-chemo and dual ICI-based regimens. These findings support personalized therapy selection but await confirmation by head‑to‑head trials. Future studies should address CPS &lt; 1 and explore optimized combinations to enhance outcomes.</p> Graphical Abstract <p></p>