The current work focuses on the effect of silica and titania nanotubes and their synthesis conditions on the potential antibacterial activity. Since most investigations are oriented towards carbon nanotubes, we focused on studying the biological activity of oxide nanotubes obtained under different synthesis and different thermal treatment conditions. The antibacterial activity against Bacillus sphericus, Bacillus subtilis, Escherichia coli and Virgibacillus halodenitrificans were examined by the plate counting method. The biological activity was evaluated as dehydrogenase activity. The results revealed that titania nanotubes exhibit a higher antibacterial activity as compared with silica. This activity could be correlated with differences in the structure and morphology of these two types of nanotubes investigated.