OBJECTIVE: To investigate the benefits of autologous platelet-rich plasma (PRP) for women with thin endometrium who received frozen-thawed embryo transfer (FET) cycle and to explore the underlying mechanism. STUDY DESIGN: This was a retrospective cohort study of 100 frozen-thawed cycles at the Reproductive Medicine Center of Putian University affiliated Hospital between January 2019 and February 2021. The women with thin endometrium were enrolled in this study. The thin endometrium criteria is endometrial thickness of <7 mm on the conversion day of previous therapy cycles. The women were divided into 2 groups according to whether they received PRP treatment. Those who received intrauterine PRP infusion during their FET cycle were the PRP group (n=66). ET was performed 3 days after the autologous PRP infusion. Those who did not receive intrauterine PRP infusion were included in the control group (n=34). The endometrial thickness, embryo implantation rate, and clinical pregnancy rate were compared between the 2 groups. RESULTS: Our analyses showed better assisted reproductive technology (ART) outcomes in the PRP group. There were significant differences between the 2 groups with regard to endometrial thickness, embryo implantation rate, and clinical pregnancy rate. CONCLUSION: In clinical practice it was demonstrated that the ART outcome of the women with thin endometrium was improved by intrauterine PRP infusion. © Science Printers and Publishers, Inc.