2017 Elsevier Ltd. All rights reserved. Learning and memory serve a critical function in allowing organisms to alter their behavior in the face of changing environments. The present chapter considers the nature and mechanisms of emotional learning and memory, particularly the acquisition and expression of memory for aversive (fearful) events. Of particular importance in this regard is work in animals, which have taken advantage of invasive techniques to yield extensive information into the biology of emotional learning and memory systems. Hence, extensive coverage is given to the anatomy and physiology of brain systems involved in fear memory based on experimental investigations in animals.