Influence of hydrodynamic conditions oil the behaviour of an inhibitor film used in the high speed mechanical field is studied. Experimentations are realized with a Rotating Disk Electrode (RDE). Electrochemical Impedance Spectroscopy (EIS) is carried out at the corrosion potential and also at anodic and cathodic over voltages under various rotation rates and after different immersion times. EIS technique is used to determine the beneficial effect of hydrodynamic conditions on the film formation. This technique characterizes also inhibitive layer modifications for high electrode rotation speeds and after long immersion times. Different analyses, XPS and AFM, were carried out and have confirmed film structure evolution with flow conditions. (c) 2005 Elsevier Ltd. All rights reserved.