The common experimental methods used in the laboratory for the study of corrosion-fatigue are based on the evolution of global mechanical and electrochemical variables in relation with environment, mechanical loading or microstructure. For a better understanding and modelling of the physical- chemical processes involved in crack initiation and propagation, it is necessary to make use of techniques giving access to quantitative informations at local scale. Recent results concerning the breakdown of passivity, the morphology and the growth kinetics of potential initiation sites, the corrosion processes at crack tip and quantitative fractography are briefly reviewed.