ObjectiveThe aim of the present study was to examine the relation between the PON1 polymorphisms and recurrent pregnancy loss (RPL).MethodsIn a cross-sectional study, blood samples were collected from 100 females. DNA was extracted and PON1 genotypes were determined by polymerase chain reaction (PCR) amplification.ResultsRegarding PON1 L55M, the mutated allele (M) frequency was found in 70.5% in RPL and in 53.5% in controls; the M allele was signiﬁcantly associated with an increased risk of RPL (adjusted odds ratio [ORadj]= 2.07; 95% confidence interval [CI];p< 0.001). However, regarding PON1 Q192R, the R mutated allele frequency was found in 28.5% in RPL and in 33% in controls. The R allele did not show any risk for RPL (ORadj0.81; 95%CI;p= 0.329).ConclusionThe present study suggests that there is an effect of genetic polymorphism on RPL and provides additional evidence that combines with the growing information about the ways in which certain PON1 genotypes can affect the development of the fetus in the uterus.