Objective: Disruption of apoptotic balance in cells during embryonic development can lead to pregnancy losses. In this study, the relationship between unexplained recurrent pregnancy loss (RPL) and apoptotic inducing death receptor-4 (DR-4) gene polymorphisms was investigated. Material and Methods: In this study, genomic DNA was obtained from 70 women diagnosed with RPL and 70 women as a control group. The polymorphisms of rs6557634 G422A in the 3rd exon of the DR-4 gene, rs20575 C626G in the 4th exon and rs20576 A683C in the 5th exon were determined in both groups using the polyme rase chain reaction-restriction fragment length polymorphism method. Results: It was determined that the incidence of C626G polymorphism, which is a missense variant in exon 4 resulting in the change of threonine to arginine in the 209th codone in the extracellular TRAIL ligand binding domain of DR-4, increased in RPL cases compared to the controls. For the investigated exon 3 and exon 5 polymorphisms, no statistical difference was observed between the RPL and the control group. Conclusion: We conclude that the missense exon 4 polymorphism in the DR-4 gene, which we detected in patients with RPL, may cause pregnancy losses through the invasion of the embryo to the uterus during embryonic development and the disruption of the apoptotic balance in its immunological tolerance.