To establish a basis for the treatment of open injuries, a bacteriological study of fresh open and festering wounds following trauma was performed. Clinical specimens were directly collected from the wounds by inserting TranswabR into the wounds, followed by bacteriological examinations. Of 213 fresh open wounds, 131 cases were polluted by bacteria and compared to the control group of 57 cases of festering wounds. All 4 of the fresh open wounds that became festered were bacteriologically polluted on their first examination. Of these 4 cases, three were open fractures. On the other hand, no case festered when the wound was proven to be aseptic on the first examination. Bacteria were detected from the wounds more frequently in summer than winter. Coagulase-negative Staphylococcus was most frequently detected and Bacillus cereus, the next. Other species with clinical importance were S. aureus, S. epidermidis, S. milleri, E. faecalis, Aeromonas species, and Clostridium species. Compared with fresh wounds, S. aureus and GNR were detected more frequently in festering wounds.