Objective This meta-analysis aims to explore the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and susceptibility to prostate cancer (PCa). Methods We searched studies related to ACE I/D polymorphism and susceptibility to PCa through PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases from inception to June 1, 2022. Five gene models, including allelic, dominant, recessive, homozygote, and heterozygote models, were analyzed. The pooled odds ratio (OR) was calculated using Stata 15.0 software. Publication bias was judged by the funnel plot and Egger’s test, with the robustness of the findings verified by sensitivity analysis. Results Eight published articles (including ten studies) were identified. The pooled results showed that ACE I/D locus polymorphism was significantly correlated with the risk of PCa under all gene models except for the heterozygous model (D vs. I: OR= 1.58, 95% CI: 1.14–2.21; DD vs. DI+II: OR=1.68, 95% CI: 1.11–2.54; DD+DI vs. II: OR=1.76, 95% CI: 1.11–2.80; DI vs. II: OR= 1.44, 95% CI: 0.99–2.10; DD vs. II: OR= 2.12, 95% CI: 1.15–3.93). Subgroup analysis based on genotype frequencies in the control group meeting Hardy-Weinberg equilibrium showed statistically significant differences in all gene models. The funnel plot and Egger’s test indicated no publication bias. The sensitivity analysis verified the robustness of the conclusions obtained in this meta-analysis. Conclusion ACE I/D locus polymorphism correlates to PCa risk. Allele D, genotype DD+DI, and DD at the ACE I/D locus increase susceptibility to PCa and can therefore serve as a potential diagnostic and screening molecular marker for PCa patients.