The aim of this study was to investigate the role of PON1Q192R and L55M single nucleotide polymorphisms(SNPs) and its association with the maternal levels of lipid parameters in gestational diabetes mellitus(GDM) and preeclampsia(PE). Ninety-nine pregnant with GDM, 97 pregnant with PE and 98 healthy pregnant were included in the study. No statistically significant difference was observed in the alleles or in the genotypes frequencies of SNPs between groups. In GDM patients, total cholesterol was higher in MM genotype of L55M gene (p < .05); Lp(a) were lower in LM genotype of the gene compared to their respective control (p < .05). In PE, HDL-C levels were higher in LM genotype (p < .05); LDL-C levels were lower in MM genotype of the gene compared to their respective control (p < .05). In PE patients, malondialdehyde(MDA) were higher in QQ genotype compared to their respective control (p < .05). Triglyceride levels were higher in PE patients with QR genotype compared with GDM patients with QR genotype (p < .05). Our results indicated that lipid profiles, Lp(a) and MDA levels showed significant differences in GDM and PE pregnants. These findings support the importance of the lipid profile, oxidized lipid and Lp(a) in different genotypes of L55M and Q192R in Turkish pregnant women with PE/GDM suggesting their roles in etiopathogenesis in these pregnancy-related disorders.