Objective To determine the associations of single nucleotide polymorphism (SNP) in leptin (LEP) genes and environmental factors with cholesterol gallstone in southeast Han populations. Methods A 1∶2 matched case-control study was conducted involving 200 patients with cholesterol gallstone. Genotyping of the SNP was examined on the LightCycler480 PCR platform using in-house high resolution melting (HRM) approaches. Detection correctness was validated through direct sequencing. Multifactor dimensionality reduction (MDR) analysis was applied to examine the effects of potential gene-environment interactions. Results Three genotypes of LEP G2548A were obtained by HRM genotyping, including 52 cases of GG wild type, 192 cases of GA mutant heterozygosity and 356 cases of AA mutation homozygous type. The genotype distribution of the SNP locus in the control group was in line with the Hardy-Weinberg genetic balance (P>0.05). The AA genotype carriers of LEP G2548A had significantly higher serum leptin than the GA/GG genotype carriers (H=6.83, POR)=5.012, 95% confidence interval (CI): 3.248-7.734〕, AA genotype of LEP G2548A site (OR=2.292, 95%CI: 1.012-5.193), family history of gallstones (OR=2.984, 95%CI: 1.329-6.700), high SBP (OR=1.927, 95%CI: 1.140-3.255) and smoking (OR=1.717, 95%CI: 1.006-2.928) were predictors of cholesterol gallstone. However, regular drinking of strong