One of the major challenges faced by the biomedical industry is the development of robust synthetic surfaces that can resist bacterial colonization.Much inspi-ration has been drawn recently from naturally occurring mechano-bactericidal surfaces such as the wings of cicada (Psaltoda claripennis) and dragonfly (Diplacodes bipunc-tata)species in fabricating their synthetic analogs.However, the bactericidal activity of nanostructured surfaces is observed in a particular range of parameters reflecting the geometry of nanostructures and surface wettability. Here, several of the nanometer-scale characteristics of black silicon(bSi)surfaces including the density and height of the nanopillars that have the potential to influence the bacteri-cidal efficiency of these nanostructured surfaces have been investigated. The results provide important evidence that minor variations in the nanoarchitecture of substrata can substantially alter their performance as bactericidal surfaces.