Understanding the many roles that corticotropin-releasing hormone ( CRH) plays in facilitating the ordinary and extraordinary events that an individual faces during a lifetime is a complex task, and yet this knowledge is fundamental to understanding our own behaviour and physiology. During the past 25 years, the study of CRH in nonhuman primates, our closest genetic relatives, has grown rapidly. The intention of this review is to provide a broad overview of the research areas in which CRH has been investigated in monkeys and apes. The review begins with a detailed description of what we know about CRH, CRH receptors, and their distribution in the brain and periphery. The narrative then follows the life cycle, from the role of CRH in fertility, pregnancy and parturition, to the shaping of behaviour and neural processes by stressful experiences early in life. CRH is also examined in the context of its other regulatory roles, including appetitive behaviour and immune responses. Finally, the review examines the insights that nonhuman primate research offers us as to how CRH helps to shape our behaviour, whether it be our ability to socialize with our peers or to be a good parent.