An observational retrospective study of cases was carried between January of 2004 and July of 2005 at the Hospital Militar Central in Bogota Colombia. One hundred and seven patients hosting injuries by guns, grenades and anti-personal mines were treated. All of the patients were tested for bacteriological analysis in the bones and soft tissues. Bacteriological isolates were tested for antibiotic sensitivity. The most common found micro-organisms were S. aureus, E. coli, Enterobacterium cloacae and faecalis, and anaerobic sp. All of the patients presented open fractures grade III A, B or C associated to the injury at war. The 60% of the wounds by mines presented with Enterobactericeae. In regards to the antibiotic sensitivity, we observed a high percentage of resistance to the anti-bacterial agents of fi rst election such as oxacilin and to the fi rst generation of antibiotics, cephalosporins.