Abstract Introduction: Tuberculosis (TB) is a curable disease that most often affects the lungs. Although it is curable, half of the patients continue to experience the aftereffects of obstructive, restrictive, or mixed patterns of lung disease, which can lead to infectious exacerbations and mortality. Studies show that patients with post tuberculosis lung disease (PTLD) have higher rates of bronchiectasis compared to other pathologies. Despite this large effect, there has been little emphasis given to the problem, making it a challenge for post-TB survivors. Objective: To assess the magnitude and associated factors of post tuberculosis (TB) bronchiectasis among bronchiectasis patients who have follow up at Tibebe Ghion Specialized Hospital (TGSH) in year 2021 to 2023. Methods: a hospital-based cross-sectional study design was used to collect data from 356 bronchiectasis patients’ cards 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 bronchiectasis among bronchiectasis is 71.3% (66.4%-75.8%). In multivariate logistic regression analysis, underweight (AOR = 16.083, 95% CI [1.706, 151.616]), longer duration of symptom (AOR = 2.813, 95% CI [1.956, 4.046]), both lung (AOR = 17.004, 95% CI [2.792, 103.549]) and upper love involvement (AOR = 22.073, 95% CI [3.330, 146.326]), and biomass fuel exposure (AOR = 8.116, 95% CI [1.879, 35.051]) were statistically significant associated factor with post TB bronchiectasis. Conclusion: The majority of bronchiectasis patients who have followed up at TGSH had post-TB bronchiectasis. The study showed that longer symptom duration, being underweight, and biomass fuel exposure were significantly associated factors. Therefore, early detection, good nutrition, and limiting biomass fuel exposure are necessary.