Background: Chlamydia trachomatis is a prevalent sexually transmitted bacterium that significantly impacts reproductive health, especially in women. Its infection rate is notably higher than gonorrhea, with over 1.6 million cases reported in 2021. Often asymptomatic, it can lead to severe complications like tubal damage, infertility, and ectopic pregnancy. Aim of the study: The study aims to identify the risk factors for ectopic pregnancy and explore the potential association between serological evidence of Chlamydia infection with ectopic pregnancy. Methods: This prospective case-control study analyzed Chlamydia trachomatis infection associated with tubal ectopic pregnancy at the Department of Obstetrics and Gynecology, Community Based Medical College Hospital Bangladesh (CBMCB) from January 2024 to December 2024. Ninety-six participants were equally divided into case (N=48) and control (N=48) groups. The case group included women diagnosed with tubal ectopic pregnancy, confirmed histopathologically, while the control group consisted of women with uncomplicated second-trimester pregnancies. Serological assays measured Chlamydia IgG antibodies using BIOS Chlamydia T. IgG ELISA kits. Data were analyzed with SPSS software. Result: The age distribution showed significant differences, with more participants aged 20–24 in the control group (50%) than in the case group (29.17%) and more aged 25–34 in the case group (52.08%) than in the control group (27.63%). Marital status was also significant, with all control group participants married and 12.5% of the case group single. The case group had higher IgG titers and chlamydial antibodies. Significant differences were found in parity, history of ectopic pregnancy, PID, and infertility, with higher rates in the case group. No significant differences were found in occupation, residence, smoking, or other factors. Conclusion: This study found a significant association between Chlamydia trachomatis infection and increased risk of tubal ectopic pregnancy. Women with ectopic pregnancies had higher Chlamydia IgG titers. The findings highlight the importance of early screening and treatment of chlamydial infections to prevent complications like pelvic inflammatory disease and tubal damage.