The purpose of this study was to compare the relative affinity of bacterial lipopolysaccharide for two casting alloys with varied surface finishes by measuring lipopolysaccharide adherence and elution. Air borne particle abraded and polished Rexillium III and Harmony Hard alloy discs were exposed to 600,000 endotoxin units/mL E. coli lipopolysaccharide in water for 24 hours, whereas control discs were placed in 37 degrees C, lipopolysaccharide-free water. Lipopolysaccharide-exposed and control discs were then transferred every 24 hours to fresh, lipopolysaccharide-free water for up to 96 hours, and previously incubated eluates were tested for the presence of lipopolysaccharide. Initial lipopolysaccharide adherence to abraded Rexillium III discs was significantly greater than lipopolysaccharide adherence to the other groups (P .05). Polished and abraded Rexillium III also exhibited significantly greater lipopolysaccharide elution (P = .0001). However, after 96 hours, more than 99% of the initially adhering lipopolysaccharide remained on both Rexillium III and Harmony Hard discs, regardless of surface treatment.