ObjectiveTo systematically evaluate pharmacoeconomic studies on Programmed cell death-1/Programmed cell death-ligand 1 (PD-1/PD-L1) inhibitors for advanced gastric cancer (GC) globally, providing evidence for healthcare policy formulation and clinical decision-making. MethodsWe conducted electronic searches in PubMed, Cochrane Library, Web of Science, ScienceDirect, Embase, CNKI, WanFang Data, and VIP databases, retrieving relevant literature published from database inception to February 2025. Two researchers independently screened the literature, extracted data, and assessed study quality using the CHEERS 2022 checklist. We systematically summarized and analyzed the basic characteristics, model structures, methodological approaches, and economic outcomes of the included studies through inductive analysis. ResultsA total of 15 studies were included, with overall good quality. All included studies employed cost-utility analyses, among which 9 utilized partitioned survival models and 6 adopted Markov models. Direct medical costs were used as the cost calculation basis in all studies. Economic evaluations showed that most PD-1/PD-L1 inhibitors combined with chemotherapy were not cost-effective compared with chemotherapy alone. However, in patients with high PD-L1 expression, PD-1/PD-L1 inhibitor-based combination therapy demonstrated cost-effectiveness for advanced gastric cancer treatment. ConclusionThe economic viability of PD-1/PD-L1 inhibitor-based combination therapy for advanced GC varies significantly across regions due to drug pricing, economic status, and national contexts. Although most current regimens are not cost-effective, their clinical efficacy advantages suggest substantial future potential. Reducing drug prices is recommended to enhance drug accessibility in China.