OBJECTIVE : Are single nucleotide polymorphisms of microRNAs (miRNAs) and risk of idiopathic recurrent pregnancy loss (RPL) associated? METHODS : A total 375 patients with idiopathic RPL (age, mean ± standard deviation [SD] 33.02 ± 4.24 years; body mass index [BMI], mean ± SD, 21.57 ± 3.70 kg/m2) and 276 control participants (age, mean ± SD, 33.01 ± 5.27 years; BMI, mean ± SD, 21.58 ± 3.20) were recruited. Pregnancy loss was diagnosed using human chorionic gonadotrophin concentrations, ultrasonography and/or physical examination prior to 20 weeks of gestation. The genotype of the participants was determined by polymerase chain reaction restriction fragment length polymorphism analysis. Statistical analysis was performed to investigate the differences in frequencies between the control and RPL genotypes RESULTS: The miR-150G>A heterozygous genotype was significantly associated with increased risk of RPL (adjusted odds ratio 2.502, 95% confidence interval 1.555-4.025; P = 0.0002). The miR-1179A>T heterozygous genotype was significantly associated with decreased risk of RPL (adjusted odds ratio 0.633, 95% confidence interval 0.454-0.884; P = 0.007). Some allele combinations that included miR-150A or miRNA-1179T resulted in an increase or decrease in risk of RPL, respectively. CONCLUSIONS : The miR-150G>A and miR-1179A>T polymorphisms were more frequently associated with RPL compared with controls.