Corrosion fatigue refers to the phenomenon of cracking in materials under the combined actions of fatigue loading and a corrosive environment. This article focuses on the various mechanisms of corrosion fatigue, namely, hydrogen-assisted cracking, anodic dissolution, and surface energy reduction. It discusses the variables affecting corrosion fatigue. The effect of fatigue load frequency, environment, grain size, stress ratio, waveform, and temperature fatigue crack growth are also discussed.