Abstract The studies posits that there is not sufficient evidence to support the use of intrauterine platelet-rich plasma (PRP) infusion in patients with recurrent implantation failure (RIF). This study aims to investigate the effects of infusion of PRP on patients with unexplained-RIF in fresh and frozen embryo transfer (ET) cycles. A total of 80 participants were included in this study. The participants were randomly assigned to one of two groups with and without PRP infusion.