Objective: Thoracic firearm injuries (TFI) have become increasingly prevalent in children. Our purpose is to assess the injury pattern, Injury Severity Score (ISS), length of hospital stay (LOS), management and outcome of children with TFI with respect to the type of injury and to evaluate the value of ISS for predicting injury severity and the eventual need for thoracotomy, as well as the rate of morbidity and mortality. Methods: Between January 1987 and June 2002, 110 children (88 boys and 22 girls) less than or equal to 16 years of age with firearm injuries to the chest were evaluated. The children were divided in four groups according to cause of injury. An ISS was calculated for each child. Those children who died before admission were excluded from the study. The relationship between ISS and prognostic factors was analyzed in all four groups. Results: The mean age was 11.1 +/- 3.0 (range 3 - 16) years. Eighty-eight (80%) were male and 22 (20%) were female. The causes of firearm injuries were high-velocity gunshot wounds (HVGSW) in 52 (47.2%), low-velocity gunshot wounds (LVGSW) in 23 (20.9%), shotgun wounds (SGW) in 18 (16.3%), and explosives wounds (EW) in 17 (15.4%). Lung injury Occurred in 72 (65.5%) patients. Tube thoracostomy was sufficient in 76.3% (84 of 110) for thoracic injury. The morbidity rate was 16.3% (18/110) and the mortality rate was 4.5% (5/110). Mean ISS was 16.62 +/- 8.2 (range 4-48). Fifty-eight patients (52.7%) had an ISS : 16, while 31 (28.2%) had a score between 17 and 25, and 21 (19.1%) had a score greater than 25. The need for thoracotomy, as well as the rate of morbidity and mortality were significantly higher in children for those with an ISS >25. SGW and EW groups had a significantly higher ISS. The mean LOS was 10.84 +/- 4.7 days (range 4-42). The value of LOS was significantly higher in children with SGW and EW. Conclusion: The majority of TFI in children can be treated successfully by tube thoracostomy if there are no gross pulmonary lacerations and airway injuries. SGW and EW were commonly associated with higher ISS and LOS. The ISS was found to be an independent predictor of the need for thoracotomy, as well as for rates of morbidity and mortality. (C) 2003 Elsevier Science B.V. All rights reserved.