The bacterial attachment response on titanium surfaces with various degrees of nano-roughness in the range of 14 nm to 0.6 nm has been investigated. Titanium surfaces were fabricated from commercial purity grade 2 (as-received) titanium, titanium modified by equal channel angular pressing (modified titanium) and titanium thin film of 12 nm and 150 nm obtained using a magnetron sputtering system. The chemical composition, wettability and surface architecture of Ti surfaces were characterised using X-ray photoelectron spectroscopy, contact angle measurements and atomic force microscopy. Two human pathogenic bacteria, Staphylococcus aureus CIP 68.5 and Pseudomonas aeruginosa ATCC 9025 were found to respond differently to each of the tested surfaces. The results indicate that bacteria can differentiate between surfaces with the fine (less than 1 nm) change of topographic characteristics, the number of retained cells differing by a factor of up to 2.