AimThe effect of intrauterine infusion of platelet‐rich plasma (PRP) which has been shown to improve the pregnancy outcomes in patients suffering from repeated implantation failure (RIF), is intended to be studied in patients with normal endometrial thickness.MethodsWe recruited 85 patients with RIF and normal endometrial thickness (≥7 mm). After obtaining their consent, they were stratified into the intervention (PRP) and control groups, according to the patient's decision. Out of 85 participants, 42 received PRP, while 43 were included in the control group. In the PRP group, 1 mL of PRP was extracted from 10 cc of whole blood via two rounds of centrifugation and infused 2 days before the embryo transfer (ET).ResultsThe pregnancy outcomes, including biochemical, clinical and ongoing pregnancy (≥20 weeks of gestation) rates were similar between the PRP (35.7, 31.0 and 26.8%, respectively) and control (37.2, 37.2 and 25.6%, respectively) groups.ConclusionWe concluded that PRP is not an effective adjuvant treatment for in vitro fertilization of patients with RIF and normal endometrial thickness undergoing ET.