The effects of selective intestinal decontamination on the bacterial colonization of burn wounds were investigated in experimentally burned mice. Prior to scalding pathogen-free mice were pretreated with bacitracin to induce intestinal overgrowth of Enterobacteriaceae. Mice treated for 20 days postburn with oral aztreonam had significantly reduced enterobacterial wound colonization compared to untreated controls. This study indicates that burn wound colonization is altered by selective decontamination of the intestinal tract.