Our aim was to evaluate the susceptibility of bacterial biofilm formation and the metabolic changes occurring in the bacterial cells by the action of ivy, strawberry tree, lavender, sulla and tree of heaven monofloral honeys. Listeria monocytogenes was the most sensitive bacteria with percentages of biofilm inhibition up to 72.20%. Pseudomonas aeruginosa was less sensitive, but tree of heaven and sulla honey caused an inhibition of biofilm up to 40.41% and 35.85%, respectively. The tree of heaven honey acted on the P. aeruginosa metabolism (75.24%). Staphylococcus aureus, majorly resistant to the biofilm-inhibitory action of the honey, was more sensitive at the metabolic level (61.63% inhibition in the presence of the tree of heaven honey).