This chapter begins with a summary of the initial findings on the effects of insula lesions on smoking behavior as well as more recent human‐lesion studies that replicate and extend this work. It further examines the role of the insula in appetitive motivational processes that drive addictive behavior, interoceptive functions that are relevant to drug addiction, and impulse control and decision‐making processes that modify addictive behavior according to conflicting goals and negative consequences. The chapter presents a unified model that integrates these seemingly disparate aspects of insula function, focusing on the role of the insula in subjective craving and drug seeking in the face of risk and conflict. A number of studies have suggested that abnormalities in insula function during executive and impulse control processes play a role in promoting addiction. A number of psychosocial treatments for addiction also work by reducing the incentive value of drugs and related stimuli.