Background: Chest tube thoracostomy is frequently performed in the emergency department (ED) for patients with traumatic thoracic injuries. However, this procedure is associated with a high complication rate. Aim Statement: The aim of this study was to describe and assess predictors of complications following chest tube thoracostomy. Measures & Design: A retrospective chart review was conducted in a level 1 trauma center. Patients aged ≥16 who required a chest tube for a traumatic injury between 2016 and 2019 were identified. Variables including demographic data, Charlson Comorbidity Index, mechanism of injury, Injury Severity Score (ISS), chest tube insertion and technique (i.e. position, dislodgement, obstruction, organ perforation), complications and interventions were collected using a standardized data collection form. A second reviewer assessed all ambiguous files. Descriptive statistics and adjusted odds ratios were calculated. Evaluation/Results: 179 patients were included in the study, of which 141 were male (79%). Mean age was 54 18 and median ISS was 17 (Q1-Q3: 9-27). 207 chest tube thoracostomies were performed for pneumothorax (81%) or a hemothorax (38%) mainly after a blunt injury (92%). 183 standard chest tube (88%) and 24 pigtail catheters (12%) were installed. Overall, emergency medicine physicians/residents performed 70% of these procedures and 54% were performed by residents. Sixty-one patients (34%) suffered a total of 73 complications: 45 were infectious (62%) and 28 were technique-related (38%). Pneumonia was the most frequent complication (19%) followed by reintroduced or replaced chest tube (12%). After adjusting for the ISS, there was no statistically significant association between the type of tube (OR 0.36 95% CI: 0.08-1.68), the medical specialty (OR 1.19 95% CI: 0.55-2.58) or the level of training (OR 1.29 95% CI: 0.63-2.64) of the clinician and the incidence of at least one complication. Discussion/Impact: Our results show that one out of three patients experienced at least one complication following a chest tube thoracostomy in the ED, which confirmed existing literature (5%- 38%). After adjustment, the type of tube used, the specialty and level of training of the health professional who performed the procedure was not associated with the incidence of at least one complication.