Genetic and environmental factors are important for the development of nonalcoholic fatty liver disease (NAFLD). The aim of the present study was to examine the single nucleotide polymorphism (SNP) -129C/T (rs17883901) in glutamate-cysteine ligase catalytic subunit (GCLC) and SNPs I128T (rs3816873) and Q95H (rs61733139) in microsomal triglyceride transfer protein (MTTP) in NAFLD. Eighty-three patients with a diagnosis of NAFLD and 93 healthy subjects were included in the study. Tetra amplification refractory mutation system-polymerase chain reaction was designed to detect the SNPs. There were no significant differences in the polymorphism of -129C/T (rs17883901) of the GCLC gene among NAFLD and control groups (p > 0.05). A significant difference was observed between NAFLD and control group regarding the SNP I128T (rs3816873) in the coding region of the MTTP gene (p < 0.05). The CT genotype increased susceptibility to NAFLD (OR: 2.467; 95% CI: 1.253-4.854; p = 0.008). No significant difference was found among the groups regarding the SNP in the coding region of MTTP gene Q95H (rs61733139). In conclusion, MTTP rs3816873 polymorphism might be a candidate to determine susceptibility to NAFLD. Larger studies are necessary to confirm these findings in various populations.