The addition of 1% chlorhexidine digluconate to 1% silver sulfadiazine cream (CDSS) was compared with 1% silver sulfadiazine (SS) alone to assess the antibacterial effect of a once-daily application of the therapies on an experimental rat model with a 20% full-thickness burn wound seeded with 108microorganisms originally isolated from infected wounds of burn patients. Separate series evaluatedStaphylococcus aureus, Psendomonas aeruginosa, Enterobacter cloacae, andStreptococcus faecalis. The mean concentration of all four organisms recovered after one week from biopsy specimens of full-thickness eschar was less in the CDSS-treated animals compared with the SS-treated animals. Microbial invasion into subjacent muscle was less frequent in animals seeded withS faecalis, while the mean concentration of bacteria recovered from muscle of animals seeded withS aureusandE cloacaewas less in animals treated with CDSS compared with those treated with SS (P< 0.05). he addition of 1% chlorhexidine digluconate to 1% silver sulfadiazine increased the antibacterial effectiveness of the latter agent.