Background: In this study, we aimed to evaluate the effect of serum lactate levels on early mortality and late wound healing in patients with childhood thoracoabdominal trauma, pre-hospital fluid replacement in patients admitted to the emergency department. Methods: This study included 479 patients under the age of 18 who applied to the emergency room for thoracoabdominal trauma between January 2014 and December 2018. Of these, 278(58%) were male, with a mean age of 8.34 years (range, 1-16 years). Demographic characteristics, fluid resuscitation, and serum lactate levels, trauma pattern, and mortality results of these patients were evaluated retrospectively. Results: 474 (98.9%) of the cases were blunt and 5 (1.1%) were penetrating trauma. 225 (47%) of the trauma cases were less than one meter falling, 162 (33.8%) were over one meter falling from the high, and 87 (18.2%) were car accidents inside and outside. Mortality was found most common in falling from height cases, which were related to prolonged hospitalization and high lactate level (p < 0.05). Wound healing times of patients undergoing pre-hospital fluid resuscitation and wound healing times of patients without pre-hospital fluid resuscitation were compared. Multivariate regression analysis, lactate level, and wound healing time were found to be predictive of the values found to be significant in the univariate regression analysis with fluid resuscitation and mortality (p < 0.05). Conclusion: Most thoracoabdominal traumas can be treated with conservative methods. Pre-hospital fluid treatment in severe trauma cases may lead to decreased lactate levels, reduced mortality, and shortened wound healing time.