¹Department of Animal Science, Faculty of Agriculture, Atatürk University, TR-25240 Erzurum - TÜRKİYE DOI : 10.9775/kvfd.2025.33854 In this study, the association between FASN gene polymorphism and milk production traits in dairy cattle was examined through a systematic review and meta-analysis. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed for the analysis. The following databases were utilized: Google Scholar, Web of Science, PubMed, Taylor & Francis, Wiley Online Library, ResearchGate, Springer, and NCBI. The analysis was executed using the co-dominant model. Standardized mean differences (SMDs) and 95% confidence intervals were calculated using both random and fixed effect models to determine the effect size of the FASN gene polymorphism on milk production traits. All data were analysed using Stata 11.2 software. The results of the meta-analysis demonstrated statistically significant associations between FASN gene polymorphism and yield traits (P<0.05). The AA genotype exhibited a notable advantage over other genotypes with respect to milk and protein yield (P<0.05), and all genotype mean differences were statistically significant for fat yield (P<0.05). A subsequent analysis revealed no statistically significant differences between the genotypes concerning fat percentage or protein percentage (P>0.05). The results of the meta-analysis indicate that, in the context of marker-assisted selection in the field of dairy cattle breeding, the utilization of AA genotyped individuals can be advantageous in enhancing milk and protein yield. Keywords : Meta-analysis, FASN, Polymorphism, SMD, Milk production traits