Summary Introduction: In recent years much attention has been paid to the possibly significant role of the activity differences of factor VII (FVII) in the etiology of recurrent miscarriages. Objectives: The aim of study was to evaluate the frequency of Arg353Gln genetic polymorphism of coagulation factor VII and the role of presence of Gln353 allele in the group of women with two or more spontaneous abortions in the first trimester of pregnancy. Material and methods: 104 women (average age 30.15+/-4.07 years) ,with two or more spontaneous abortions in the first trimester (between 6 and 13 weeks of gestation) of pregnancy, and 163 healthy women (average age 29,40+/-3,56 years), with at least one pregnancy which had ended with the delivery of a healthy newborn, have been analyzed. The frequency of genotypes has been determined by means of polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) methods. Results: In the group of recurrent miscarriages, higher frequency of homozygotic Arg353/Arg353 genotype (82.69 vs 74.85%) and lower frequency of heterozygotic Arg353/Gln353 (17.31 vs 25.15%) genotype have been noted, comparing to the control group. Frequency of mutatedGln353 allele was lower in the group of spontaneous abortions (8.65 vs. 12.58%, ns). Observed frequency of mutated Gln353 allele in the control group (12.58%) was compatible with th frequency for Caucasian observed by other authors. In the subgroup of women with two (80 women), three or more abortions (24 women), the frequency of heterozygous genotype Arg353/Gln353 was lower if compared to the controls (16.25% and 20.83%, respectively) (controls 25.15%, ns). Lower frequency of heterozygous genotype Arg353/Gln353 in the subgroup of women with abortions in the early (6-9 week of gestation) period of the first trimester (13.85 vs 25.15%, p=0.04) has been observed. Conclusion: Research and investigation which have been carried out suggest a weak connection of Arg353Gln polymorphism of coagulation factor VII with the frequency of recurrent miscarriages. However, higher frequency of Gln353 allele in the control group of healthy women suggests its protective role in coagulation changes and recurrent miscarriages. A visibly lower frequency of heterozygous genotype Arg353/Gln353 in the miscarriages in the early period of the first trimester, which might suggest potentially great protective significance of Gln353 allele presence in this period of pregnancy, remains an interesting fact.