Proper management of highly contaminated traumatic wounds frequently requires delayed primary closure of healing by secondary intention to prevent subsequent infection. This animal study compares the efficacy of various wound debridement methodologies to prevent infection following primary closure of treated contaminated wounds. Forty-four Sprague-Dawley rats with uniform, paravertebral incisions were studied. Each wound was inoculated with a standard amount of Staphylococcus aureus bacteria and allowed to remain open for two hours. Each wound was treated before wound closure by one of four debridement methods: (1) surgical scrubbing, (2) high-pressure irrigation, (3) ultrasonication, or (4) soaking. The control animals' wounds were closed without debridement. At 7 days, each animal was evaluated for the presence of gross infection and wound induration. Ultrasound, with a 25% incidence of gross infection, compared with irrigation (75%), scrubbing (82%), and soaking (89%) provided significant protection from subsequent abscess formation. The control group uniformly developed infection (100%). The average amount of induration after ultrasonication (1.35 +/- 0.56 cm) was also significantly less than irrigation (2.07 +/- 0.75 cm), scrubbing (1.95 +/- 0.34 cm), and soaking (1.73 +/- 0.22 cm). Our data demonstrate that ultrasonic wound debridement has exciting potential as a new debridement technique for contaminated traumatic wounds.