Trial-based economic value of prevention programs for diabetes is inexplicit. We aimed to review the cost-effectiveness of nonpharmacological interventions to prevent type-2 diabetes mellitus (T2DM) for high-risk people. Six electronic databases were searched up to March 2022. Studies assessing both the cost and health outcomes of nonpharmacological interventions for people at high-risk of T2DM were included. The quality of the study was assessed by the Consolidated Health Economic Evaluation Reporting Standards 2022 checklist. The primary outcome for synthesis was incremental cost-effectiveness ratios (ICER) for quality-adjusted life years (QALYs), and costs were standardized in 2022 US dollars. Narrative synthesis was performed, considering different types and delivery methods of interventions. Sixteen studies included five based on the US diabetes prevention program (DPP), six on non-DPP-based lifestyle interventions, four on health education, and one on screening plus lifestyle intervention. Compared with usual care, lifestyle interventions showed higher potential of cost-effectiveness than educational interventions. Among lifestyle interventions, DPP-based programs were less cost-effective (median of ICERs: $27,077/QALY) than non-DPP-based programs (median of ICERs: $1395/QALY) from healthcare perspectives, but with larger decreases in diabetes incidence. Besides, the cost-effectiveness of interventions was more possibly realized through the combination of different delivery methods. Different interventions to prevent T2DM in high-risk populations are both cost-effective and feasible in various settings. Nevertheless, economic evidence from low- and middle-income countries is still lacking, and interventions delivered by trained laypersons and combined with peer support sessions or mobile technologies could be potentially a cost-effective solution in such settings with limited resources.