A BSTRACT Background and Aim: The National Tuberculosis Elimination Program (NTEP) has been progressive in addressing the issues related to tuberculosis (TB) control in the country, with constant programmatic changes based on evidence available from operational research. Our objectives were 1. to assess the sociodemographic and clinical characteristics, and the treatment outcomes of patients on fixed-dose combination (FDC) daily regimen and 2. to assess the factors associated with unsuccessful treatment outcomes among patients with DS-TB. Materials and Methods: A retrospective cohort study was conducted based on record review. The study population included all patients with drug-sensitive TB, registered and initiated on treatment under NTEP “new category” from January to June 2018 and under “previously treated category” from January to March 2018. Quantitative data downloaded from Nikshay in Excel format was imported. Results: A total of 8301 patients with DS-TB registered under NTEP. Mean (standard deviation [SD]) age of DS-TB patients was 35.3 + 16.9 years, and 63.2% were in the age group of 15–44 years. Also, 60.1% were male, 2.5% were human immunodeficiency virus (HIV) positive, 65.3% were pulmonary TB cases, and 70.4% obtained treatment from public providers. Proportion of “successful” and “unsuccessful” outcomes was 87.9% and 12.1%, respectively, in the new treatment category and 78.3% and 21.7%, respectively, in the previously treated category. Among the patients classified under new category, the unsuccessful treatment outcome remained significantly high after adjustments with known confounders among patients aged 45–54 years (adjusted relative risks [aRR] 1.59, 95% confidence interval [CI] 1.31–1.93) and 55–64 years (aRR 1.67, 95% CI 1.36–2.05) compared to patients aged <15 years. Conclusion: Unsuccessful treatment outcome was significantly high among patients aged 45–54 years. Various adherence mechanisms implemented can be evaluated for further upscaling and improving the program effectiveness.