Peritonitis is a serious problem associated with continuous ambulatory peritoneal dialysis. The process can be initiated by intraluminal contamination and colonization of the peritoneal cavity as well as by bacterial adhesion to biomaterials, including catheters and exit site dressings. The aim of this study was to determine the degree to which two pathogenic organisms could adhere to three biomaterial surfaces, and the extent to which dextrose concentration influenced the binding and survival. Using a 24-hour in vitro assay, it was found that the Staphylococcus aureus strain consistently adhered significantly better than the Pseudomonas aeruginosa isolate, and only the adhesion of the latter was decreased with higher concentrations of dextrose in dialysis solutions. Electron microscopy demonstrates that within this short time period, bacterial biofilms had begun to form on the catheter surfaces.