Antibiotic-impregnated polymethylmethacrylate (PMMA) bead chains are in current clinical use for prophylaxis and management of osteomyelitis. The in vivo interaction between PMMA beads and an experimentally infected wound is examined. Two modes of bacterial adherence to plain PMMA beads are demonstrated. In this report, tobramycin-sensitive bacteria did not attach to tobramycin-laden beads. Therefore, implanted PMMA beads should contain an antibiotic to which the infecting bacteria is sensitive.