The aim of this study is to determine the association between C677T polymorphism in MTHFR gene and plasma homocysteine concentration in recurrent fetal miscarriages.Overall, 100 women were included in the research, the case group comprised of 50 women who had a history of spontaneously recurrent miscarriage with unspecified cause, and 50 of whom had experienced at least two successful pregnancy, as controls. Methods used in the study included PCR-RFLP with limited effective HinfI enzyme in order to investigate MTHFR polymorphism and enzyme-linked immunosorbent assay analysis to investigate plasma homocysteine concentration.There was a significant increase in the prevalence of mutant TT genotype among women with miscarriage history. Also, the mean homocysteine level in the case group was significantly higher than that in the control group (P = 0.002) and higher level of homocysteine was found in the carriers of T allele.Our data suggest that C677TT genotype may be a risk factor for miscarriage and CC wild type genotype supposed to have protective effect on hyperhomocysteinemia.