Purpose of Investigation: To assess the effects of the diclofenac suppository pretreatment in prevention of vasovagal reflex-associated complications for infertile women undergoing local endometrial injury (LEI). Materials and Methods: Eighty-six infertile outpatients with repeated implantation failure following transfer of morphologically good embryos and/or blastocysts underwent single curettage LEI to improve the pregnancy outcome in the subsequent embryo/blastocyst transfer cycle. Of them, 35 patients chose diclofenac suppository administration prior to LEI, whereas 51 patients did not. The occurrence of palpitations, bradycardia, hypotension, presyncope, and requirement of bed rest was compared between the two groups. Results: There were no significant differences in the demographics between the two groups. The prevalence of presyncope and requirement of bed rest was significantly lower in the diclofenac suppository group than in the control group. The pregnancy outcome was similar between the two groups. Conclusion: The diclofenac suppository administration is a low-cost effective method to reduce the risk of the vasovagal reflex-associated complications in infertile women undergoing LEI.