The use of target agents and immune checkpoint inhibitors have changed the treatment landscape for AGC in the first-line setting. However, the crosswise comparison between each regimen is rare. Therefore, we estimated the efficacy and safety of targeted therapy or immunotherapy with chemotherapy in AGC patients as the first-line treatment. Included studies were divided into “average” or “specific positivity” group according to whether the patients were selected by a certain pathological expression. We conducted a Bayesian network meta-analysis for all regimens in both groups. In average group, no regimen showed significant improvements in overall survival (OS) and progression free survival (PFS), while pembrolizumab and nivolumab combined with chemotherapy were ranked first and second respectively without an obvious safety difference. In specific positivity group, zolbetuximab plus chemotherapy significantly prolonged OS (HR 0.53, 95% CI 0.36–0.79) and PFS (HR 0.45, 95% CI 0.25–0.81). The top three regimens were zolbetuximab-chemotherapy, trastuzumab plus pertuzuma-chemotherapy and nivolumab-chemotherapy respectively, with no significant safety risk. For average patients, immune checkpoint inhibitor PD-1 plus chemotherapy will be the promising regimen. For patients with overexpression of CLDN18.2, zolbetuximab combined with chemotherapy comes with greater survival benefits, while for patients who have PD-L1 expression with no HER-2 or CLDN18.2 positivity, additional immune checkpoint inhibitor of PD-1 will be a good considered option.