It has been estimated that up to 60% of American adults do not get sufficient sleep, and insomnia plays a role in the development of many medical conditions, as well as complicating the recovery from depression, anxiety, and other psychiatric conditions. Many factors can contribute to poor sleep, including lifestyle, mental health problems, other general medical problems, medications, or primary sleep disorders. This workshop discusses the importance of sleep and the consequences of insufficient sleep and presents a framework for understanding, assessing, and treating commonly encountered sleep problems. It summarizes how we sleep, including the five-stage sleep cycle, the circadian cycle, the sleep-wake cycle, and the concept of sleep arousal, and outlines the different ways changes in these can contribute to sleep problems. It differentiates between a primary sleep disorder (e.g., sleep apnoea, narcolepsy, restless legs syndrome, delayed sleep onset disorder) and primary or secondary insomnia, outlines the potential consequences of each, and summarises their management. It then reviews the major causes of insomnia and presents simple questions that can be introduced into any health or mental health assessment. It outlines a comprehensive yet succinct assessment of a sleep problem and presents simple screening tools, including a sleep log, to assist with it. It then reviews the 4 major approaches to managing a sleep problem – sleep hygiene strategies, CBT for insomnia, the use of medications, including a new approach to considering medication choice, and the use of non-prescription medications and treatments, with practical examples of all these and provides a series of handouts that can be given to people dealing with insomnia.