To investigate the role of glutathione S-transferases (GSTs) in the pathogenesis of recurrent miscarriage (RM).Genetic association study.University of Rome, Tor Vergata and San Giovanni Calibita, Fatebenefratelli Hospital.One hundred twenty-one women with RM and 113 women without pregnancy complications.Genomic DNA extracted from buccal cells and screening of positive/null genotypes of GSTM1 and GSTT1 genes and single nucleotide polymorphisms of GSTA1, GSTO2, and GSTP1 genes.Occurrence of GST polymorphisms.Women with at least one GSTA1*-69T allele are more frequent in the RM group than in the control group: 67% vs. 48%, respectively. Significant outcomes were obtained considering different genetic models: codominant, dominant, and log-additive. In addition, the combined analysis suggests that GSTA1 and GSTM1 variants have a significant interaction in RM risk.Our study highlighted a significant association between the GSTA1 gene and an increased risk of RM. In particular, the -69T allele in the GSTA1 gene may be considered as a predisposing factor of RM.