Objective Prior pulmonary tuberculosis (PTB) on chest X-ray (CXR) was commonly found in infertile patients receiving examinations before in vitro fertilization and embryo transfer (IVF-ET). It was unclear whether untreated PTB would affect pregnancy outcomes after IVF-ET. Method We conducted a retrospective cohort study of 14,254 infertile patients who had received IVF-ET at Peking University Third Hospital in 2017. Prior PTB was defined as the presence of signs suggestive of old or inactive PTB on CXR, with or without a clinical TB history. Patients who had prior PTB on CXR but had not received a clinical diagnosis and anti-TB therapy were included for analysis. Live birth, clinical pregnancy, and miscarriage rates were compared between the untreated PTB and non-PTB groups. Results The untreated PTB group had significantly lower clinical pregnancy (31.7％ vs. 38.1％) and live birth (23.8％ vs. 30.6％) rates than the non-PTB group (both P < 0.001). Multivariate analysis revealed that untreated PTB was a risk factor for decreased live birth rate [odds ratio (OR), 0.80; 95％ confidence interval (CI), 0.66–0.98; P = 0.028] in all patients and for increased miscarriage (OR, 4.19; 95％ CI, 1.69–10.39; P = 0.002) and decreased live birth (OR, 0.45; 95％ CI, 0.24–0.83; P = 0.011) rates in patients with unexplained infertility. Conclusions Untreated PTB was associated with adverse pregnancy outcomes after IVF-ET, especially in patients with unexplained infertility, highlighting the clinical significance of PTB in this specific patient population.