Aim: To investigate the influence of antibiotic- induced morphological changes on adhesion and motility abilities and surface properties of nosocomial Pseudomonas aeruginosa under different physiological states. Methods and Results: The effects of subinhibitory concentration ( sub-MIC) of Piperacillin / Tazobactam ( P / T) and Imipenem ( IMP) were studied on P. aeruginosa adhesion ( 1 h) using a modified microtitre-plate assay, on their ability to swim and to twitch, on surface hydrophobicity and on acid - base interactions of P. aeruginosa strains by measuring their ability to adhere to n- hexadecane, chloroform and ethyl acetate, respectively. Our results show that antibiotic- induced morphological changes and bacterial physiological state can affect differently surface properties, motility and adhesion abilities of P. aeruginosa. Conclusions: Under different physiological states P / T induced morphological changes, reduced motility abilities, decreased adhesion to polystyrene and cell surface hydrophobicity ( CSH). Moreover, P / T and IMP led to similar changes in exponential population adhesion to chloroform and ethyl acetate. Additionally, IMP induced morphological changes and showed no differences on CSH, adhesion and motility abilities in both growth phases. Significance and Impact of the Study: Adhesion is an attractive target for new antibacterial strategies, namely by using sub- MIC antibiotics that induce morphological, motility and surface properties changes, which are dependent of P. aeruginosa phenotype and physiological state.