Abstract Stainless steel disks were implanted with N +, O + and SiF 3 +, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF 3 +-implanted stainless steel performed much better than N +-implanted steel, O +-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.