AIM: Patients with thoracic trauma constitute one third of all the trauma cases, in west Sicily were recorded 941 thoracic trauma during the period between 2006 and 2009. Sicily is one of the Italian regions with the highest rate of obesity: some studies have demonstrated that obesity is an independent risk factor for mortality in high energy blunt traumas. MATERIAL OF STUDY: This study was conducted with trauma patients older than 20 years old who presented to our Department during the last five years. We only included thoracic injuries and politrauma with a thoracic involvement and a BMI >25. Patients were divided into two groups: HET and LET patients. RESULTS: Thoracic trauma was more common in patients with a BMI >25 than in normo-weight and clinic admission rate, length of hospital stay and ISS score increased in proportion with the increase of BMI. Both HET (high energy trauma) and LET (low energy trauma) revealed that overweight, obese and morbidly obese patients had greater admissions and length of hospital stay. DISCUSSION: The overweight and obese population has increased substantially over the last two decades and 61,5% of the Sicilian population is above normal weight. A large body mass with excess adiposity may contribute to HET injuries in several ways. Obesity has a number of comorbidities that reduce chances of recovery in overweight and obese patients experienced thoracic trauma both HET and LET. CONCLUSION: Obesity increases morbidity independently of injury severity in thoracic trauma patients. As BMI increased, length of hospital stay increased and prognosis deteriorates.