Objective: This study was conducted to investigate the impact of previous delivery mode on pregnancy outcomes in patients with secondary infertility after frozen-thawed embryo transfer. Methods: This prospective observational study included 140 patients experiencing secondary infertility. Of these, 70 patients had a previous cesarean delivery (CD), while the remaining 70 patients had a previous normal vaginal delivery (NVD). The primary outcome was the implantation rate. The secondary outcomes included rates of clinical pregnancy, chemical pregnancy, miscarriage, and ectopic pregnancy. Results: The comparison of all fertility outcomes between the two groups revealed no statistically significant differences. The implantation rate was 40.4% in the CD group and 41.7% in the NVD group (p=0.842). The clinical pregnancy rate was 50% in the CD group and 49.3% in the NVD group (p=0.932), while the chemical pregnancy rate was 14.6% in the CD group and 19% in the NVD group (p=0.591). The miscarriage rates in the CD and NVD groups were 20% and 17.6%, respectively (p=0.803). One case of tubal ectopic pregnancy occurred in the NVD group (1.4%). Conclusion The mode of prior delivery did not significantly impact pregnancy outcomes following frozen-thawed embryo transfer.