The antibacterial activity of cyclohexane, dichlormethane, methanol and aqueous extracts of tinder fun-gus Fomes fomentarius (L.) Fr (Polyporaceae) was tested against 9 bacterial strains (Staphylococcus aureus,Staphylococcus epidermidis, Micrococcus luteus, Bacillus subtilis, Enterococcus feacalis, Escherichia coli, Kleb-siella pneumoniae, Pseudomonas aeruginosa, Salmonella abony), as well as against 10 different clinicalisolates and one reference strain of Helicobacter pylori. Minimal inhibitory concentrations (MICs) of allextracts against 9 bacterial strains were in the range of 125–250 g/ml. Methanol and aqueous extractsshowed significant activity against H. pylori with MIC values between 4–32 g/ml. Also, cytotoxicity oftested extracts was significant. Aqueous extract was the most active one against HeLa cells with an IC508.31 ± 1.18 g/ml and N87 cells with IC5064.46 ± 3.13 g/ml without any activity against normal MRC5cell line (> 200 g/ml).