Objectives Mortality from tuberculosis (TB) has been declining since 2000, nevertheless there is still a significant number of patients who die before or during TB treatment. The aims were to examine and describe predictors associated with TB related mortality. Methods Patients notified with TB from 2009 though 2014 in Denmark were included. Data were extracted from national registers and patient records were examined for clinical information and treatment outcome. Cox proportional hazards regression was used to examine TB related mortality. Results A total of 2131 cases were identified, 141 (6.6%) patients died before or during TB treatment. TB related mortality accounted for 104 cases (73.8%) and decreased significantly from 6.7% to 3.2% (p = .04) during the study period. Within 1 months of diagnosis, 49% of TB related deaths had occurred. The strongest risk factors present at time of diagnosis, associated with TB related mortality, were: Age > 70 years, Charlson comorbidity index > 1, alcohol abuse, weight loss, anemia, and C-reactive protein > 100 mg/L (p < .05). Conclusion The majority of TB related deaths occurred soon after diagnosis, emphasizing that TB patients identified to have a high risk of mortality should be closely monitored before and during the intensive treatment period to improve their outcomes.