The present study was carried out to assess the frequencies of factor XIII (FXIII) Val34Leu genetic variation in the patients with recurrent spontaneous abortion and healthy fertile women of Azeri Turkish origin. A total of 54 patients with recurrent spontaneous abortion and 46 healthy fertile women as controls were studied for the FXIII Val34Leu genetic variation by a RFLP-PCR method. Statistical analysis showed that patients (χ2 = 2.4, p value = 0.292) and controls (χ2 = 1.035, p value = 0.596) were in agreement with Hardy-Weinberg equilibrium. The Leu allele frequency was 0.18 and 0.13 in patients and controls, respectively. FXIII Leu34Leu (homozygous for 34Leu) genotype was not found in patients and controls. FXIII Val/Leu and Val/Val genotype frequencies were 19 (35.19%) and 31 (64.81%) in patients and 12 (26.09%) and 34 (73.91%) in controls, respectively. FXIII 34Leu allele and Val34Leu genotypes were more common in the case group containing individuals with unexplained RSA but the differences of FXIII Val34Leu (G/T genotype) (odds ratio = 0.65 (0.25 < OR < 1.67) corresponding to 95% CI, χ2 = 0.96, p value = 0.32) and FXIII 34Leu (T allele) (odds ratio = 0.70 (0.30 < OR < 1.64) corresponding to 95% CI, χ2 = 0.78, p value = 0.37) was not statistically significant. These results suggest that factor XIII Val34Leu genetic variation is not associated with recurrent spontaneous abortion.