SEVERAL TEXTBOOKS AND SYMPOSIA proceedings cover the application of electrochemical methods in corrosion testing [1-16]. This chapter highlights many of the commonly used laboratory methods after presenting a brief review of thermodynamics and kinetic aspects of electrochemical reactions that describe corrosion processes. Techniques discussed include Tafel extrapolation, polarization resistance, electrochemical impedance spectroscopy, electrochemical noise resistance, use of rotating disks, and cylinders to study aspects of corrosion affected by solution flow, polarization methods for assessing susceptibility to localized corrosion, scratch repassivation, potential-step repassivation, electrochemical noise applied to pitting, potentiodynamic repassivation techniques for assessing sensitization, the barnacle electrode and permeation methods for hydrogen concentration analysis, and methods for evaluating anodized layers and coatings on metals.