I studied the effects of LC ointment made of Solbase and heat-killed Lactobacillus casei YIT 0003 on the healing of thermal injury wounds and the elimination of bacteria from infected wounds in mice. LC ointment promoted the healing of the uninfected thermal injury wounds and thermal injury wounds infected with Pseudomonas aeruginosa alone or with mixed bacterial suspension of Staphylococcus aureus, Escherichia coli and P. aeruginosa and resulted in the elimination of infecting bacteria. Histopathologically, the formation of collagen fibers in wounded subcutaneous tissues to which LC ointment was applied was more remarkable than that of tissues treated with Solbase (ointment base). The clearance of bacteria and promotion of healing of the infected thermal injury wounds due to LC ointment were superior to those of Eksalb ointment, Azunol ointment and Mafatate (mafenide acetate) cream, and almost the same degree as that of Geben (silver sulfadiazine) cream. These effects of L. casei were nearly the same or somewhat superior compared with that of other lactobacilli, and were enhanced by the addition of gentamicin or ofloxacin.