The aim of this study was to assess in vitro the improvement in release kinetics for teicoplanin and the inhibition of bacterial adhesion on calcium sulfate-soaked PMMA discs. Calcium sulfate has been used in vivo and shown to be biocompatible, and prevention of bacterial adhesion may be expected with calcium sulfate-soaked polymethylmethacrylate (PMMA). Discs were made by adding teicoplanin and calcium sulfate in powder form to PMMA powder. The antibiotic concentration eluted from PMMA discs was assayed by agar diffusion assay. Nonadherent bacteria were removed by washing and adherent bacteria were detached by sonication. The suspension including nonadherent bacteria was seeded on sheep blood agar plate and incubated for 24 h at 37 degrees C for the growth of microorganisms. The teicoplanin released from discs containing calcium sulfate was higher than that released from discs which had not been soaked with calcium sulfate. The count of bacteria adhering to the calcium sulfate-soaked discs was lower than that from the discs without calcium sulfate. In conclusion, the addition of calcium sulfate to teicoplanin-loaded PMMA bone cement may provide local antibiotic concentrations higher than MIC values due to increased antibiotic release. Furthermore, calcium sulfate was found to be effective in reducing bacterial adherence to treated discs.