Background <p>Intended to investigate the potential effects of endometrial preparation procedures on the results of subsequent frozen embryo transfer (FET) cycles in infertile women with chronic endometritis (CE) following a single course of antibiotic therapy.</p> Methods <p>From July 2020 to December 2023, 773 infertile patients participated in a retrospective research. CD138 was immunostained in endometrial tissues taken during the proliferative phase. CE was suggested by the presence of CD138-positive cells in the stromal cells. Oral antibiotics were administered to every patient with a CE diagnosis. After one course of drug treatment, patients had endometrial preparation and frozen embryo transfers. This study compared the impact of different endometrial preparation strategies on pregnancy outcomes.</p> Results <p>Four regimens, hormone replacement treatment (HRT), ovulation induction, natural cycle, and gonadotrophin-releasing hormone agonist-HRT (GnRH agonist-HRT), did not significantly alter the outcome of pregnancy in patients with CE. Compared to other groups, the ovulation induction cycle group had a higher clinical pregnancy rate and embryo implantation rate. In addition, the miscarriage rate is lower compared to other populations. Patients with treated CE who received HRT, GnRH agonist-HRT, ovulation induction cycle, and natural cycle did not differ substantially (<i>P</i> &gt; 0.05).</p> Conclusion <p>Patients with treated CE did not see any change in pregnancy outcomes as a result of endometrial preparation procedures.</p>