Abstract Background:Pulmonary tuberculosis (PTB) is one of the most common infectious diseases worldwide, and contributes significantly to morbidity and mortality in developing countries. Emerging evidence suggests that after completion of treatment for tuberculosis (TB) a significant proportion of patient’s experience post tuberculosis lung disease. Despite this large effect, there has been little emphasis given to the problem, making it a challenge for post-TB survivors. Objectives:To assess magnitude ofpost TB lung disease and associated factors among patients treated for pulmonary tuberculosis and receiving follow-up at chest clinic of Tibebe Ghion Specialized Hospital, from September 2023 to August 2024 Bahir Dar. Methods:A hospital-based cross-sectional study design was used to collect data from 342 medical records of patients who complete pulmonary tuberculosis treatment using a pre-developed data collection checklist. The data were entered to SPSS version 27 software for analysis. Various descriptive and analytical statistics were computed and results were expressed using word descriptions, tables, and figures. The association of factors was determined using bivariate and multivariate logistic regression analysis and statistical significance was determined by p-value less than 0.05 at 95%CI. Result: Overall the prevalence of post TB lung disease among patients who complete pulmonary tuberculosis treatment is 56.7%. In multivariate logistic regression analysis, living in the rural setting (AOR = 0.47, 95% CI [0.27, 0.80]), negative HIV status (AOR =0.34, 95% CI [ (0.03,3.4)]) and recurrent episodes of TB(AOR = 0.49, 95% CI [0.28, 0.84]) were statistically significant associated factor with post TB lung disease. Conclusion:More than half of patients who complete pulmonary tuberculosis treatment and visited chest clinic of TGSH had post-TB lung disease. The study showed that living in the rural setting, negative HIV status and recurrent attack of TB were significant risk factors.