The effect of the septol and lysol disinfectants on five bacterial species commonly encountered in veterinary and public health problems were examined by dilution, suspension and germ carrier tests. Their bacteriost atic concentrations fluctuated from 0.06 to 0.25% while the bactericidal ones were ranging from 1% after 2 minutes interaction time to 0.1% after 30 minutes. They could decontaminate the aluminium and ceramic germ carriers by 5% and 0.5% concentrations after an exposure of 15 120 minutes, respectively, but decontamination of the wood germ carrier needed lower concentrations of 2.5% and 0.5% after elapsing these intervals.