Background: Elevated antibody titers to Chlamydia trachomatis are detected in up to 70% of women with tubal factor infertility (TFI). In order to evaluate the influence of past chlamydial infection on the results of IVF treatment, a prospective cohort study was performed. Materials and methods: A total of 242 women with TFI were enrolled in the study. Serum samples (n ¼ 242) and follicular fluid (n ¼ 197) were analyzed using enzyme-linked immunosorbent assay for anti-C. trachomatis IgG, IgA, IgM and anti-chlamydial heat shock protein 60 kDa IgG. Results: ''Poor response'' to ovarian stimulation was two times more frequent in seropositive subjects (22.9% versus 13.3%, p ¼ 0.039). Seropositive and seronegative women had similar IVF outcomes, expressed by clinical pregnancy (20.5% versus 25.0%), life birth (13.1% versus 20.0%) and miscarriage rates (36.0% versus 16.7%, p ¼ 0.092). Incidence of missed abortion after IVF was higher in women with previous exposure to C. trachomatis (28.0%) as compared to those without antibodies (3.3%), p ¼ 0.018. Conclusions: Anti-chlamydial antibody detection is not related to oocyte maturity, embryo quality, pregnancy and life birth rates. However, past chlamydial infection in TFI patients is associated with decreased IVF success: ''poor response'' to ovarian stimulation and missed abortion rate.