The aim of our study was to determine whether early internal fixation of major bone fractures helps prevent bacterial translocation in patients with multitrauma. Thirty-seven Sprague-Dawley rats were divided into three groups: (1) anesthesia only (n = 12); (2) the trauma group: tibia and femur fractures and moderate head trauma under anesthesia (n = 14); and (3) the fixation group: fixation of tibia and femur fractures and moderate head trauma under anesthesia (n = 11). After 24 hours, mesenteric lymph nodes, liver, spleen, and systemic blood samples were quantitatively cultured. The terminal ileum was assessed histopathologically. The incidence of bacterial translocation was less in the anesthesia group (two of 12 rats) and the fixation group (two of 11 rats) than in the trauma group (10 of 14 rats). The number of organs containing viable bacteria was significantly lower in the fixation group than in the trauma group. Histopathologically, villous architecture was preserved mostly in the fixation group; however, marked mucosal damage was detected in the trauma group. Our data suggest early internal fixation of long bone fractures in polytraumatized experimental animals with head injury results in preservation of the intestinal mucosal barrier and decreased bacterial translocation from the gut.