Background: Traumatic chest injury is responsible for 10%–15% of all trauma-related hospital admissions across the world. It is also responsible for approximately 25% of trauma related death. Several predictors have been described for mortality following chest trauma however, limited published studies were available in Ethiopia. Objective: To assess mortality rate and factors associated with death in traumatic chest injury patients over five year's period from June 2016 to June 30, 2020 G.C. Method: A retrospective cross-sectional study was done from June 2016 to June 30, 2020. Data was collected from patients’ chart. The collected data was entered into Epi-info version 7 and transferred to SPSS version 20.0 for processing and analysis. Bivariable and multivariable logistic regression was used to show factors associated with mortality. P- Value < 0.05 was considered statistically significant. Result: A total of 419 patient charts were eligible for this study. The majority of patients (55.8%) sustained blunt chest injuries and violence (52.5%) was the leading cause of injuries. Hemopneumothorax (27.7.0%), hemothorax (22.9%) and rib fracture (17.2%% were the most common type of injuries. Associated extra-thoracic injuries were noted in 70.4% of patients, from those, extremity injury (22.2%), head/neck injuries (21.7%) and abdominal injuries (18.1%) were the commonest. Most patients (64.7%) were treated successfully with chest tube. Nearly, one third (35.3%) had complications including pneumonia (13.8%) and Atelectasis (12.6%). The mean length of hospital stay was 9.40 days. The overall traumatic chest injury mortality rate was 26%. Mortality was significantly associated with age >50 year [AOR 9.32, 95% CI, 2.72–31.86], late presentation beyond 6hr (AOR 7.17, 95% CI 1.76–29.21), bilateral chest injury (AOR 3.58 95% CI 1.53–8.38), penetrating chest injury (AOR 3.63 95% CI 1.65–7.98), presence of extra-thoracic injury (AOR 4.80, 95% CI, 1.47–15.72) and need for mechanical ventilation (AOR 11.18, 95% CI 2.11–59.23). Conclusion: The mortality rate in traumatic chest injury was high. Late presentation beyond 6hr, age >50-year, penetrating injury, bilateral chest injury, associated extra thoracic injury, and need for mechanical ventilation were identified as possible risk factors for mortality in traumatic chest injury patients. Highlights