This issue of Sleep Medicine Clinics will be Guest Edited by Jack Edinger, PhD, at National Jewish Health and will focus on Insomnia. Article topics include cognitive-behavioral insomnia therapy, Insomnia and Cancer, Dissemination Training for CBTI, Insomnia and short sleep duration, neurophysiology of sleep quality and insomnia, Pain, Sleep, and Insomnia, Insomnia and obstructive sleep apnea, Epidemiological studies conclusions on nature, persistence, and consequences of insomnia, pharmacological management of insomnia, Hyperarousal and insomnia, role of genes in insomnia expression, and the role of bright light therapy in managing insomnia.