In 34 rabbits, both tibiae were inoculated with Staphylococcus aureus. 14 legs received no treatment and served as controls. In 12 legs, the wound was treated with pure collagen and in 18 legs, collagen with gentamicin (Gentacoll) in a dose of 10 mg/kg body weight was applied to the wound before closure. Postoperatively 12 received 10 mg/kg body weight gentamicin intravenously and no local treatment. The animals were killed 7 days after inoculation and evaluated macroscopically and microbiologically for infection. 6 rabbits (12 legs) were used for pharmacokinetic studies only and they were killed after 2, 4, and 18 hours, respectively. 11/14 untreated legs developed a macroscopically acute osteomyelitis. No infection was found in the 18 legs treated with Gentacoll and 1/12 treated with gentamicin systemically had growth of the inoculated bacteria in tissue biopsies. The concentrations of gentamicin in the serum as well as locally reached peak values were well above the MIC value in all groups, with a maximum after 1-2 hours. No gentamicin could be detected after 18 hours, independently of the mode of administration.