The effect of TFX-Polfa administered alone or with three antibiotics on the survival time in mice infected with E.coli and S.aureus was estimated. TFX has been administered 48, 24, 2 hours before and 24, 48 and 72 hours after infection, in doses of 10 mg/kg of body weight. Ciprobay has been administered 2 hours after infection, and every 24 hours during the experiment in dose of 15, 7.5 and 3.75 mg/kg of body weight. Amikin has been used in doses of 7.5, 3.75 and 1.87 mg/kg of body weight, Cefobid in doses of 30, 15 and 7.5 mg/kg of body weight. The antibiotics have been administered 2 hours after infection and every 12 hours to the end of experiment. Animals have been observed 10 days after infection. The positive effect of TFX on the survival time in mice infected with E.coli has been observed, but this preparation has given a little effect on the tested parameter in mice infected with S.aureus. Best antibacterial effect of Ciprobay and Amikin has been observed after administration of clinical doses. However, simultaneous therapy with TFX and tested antibiotics resulted in various (positive and negative) effects on the survival time during 10 days of observation.