Healthy sleep is essential for a child’s full growth and development. To assess the quality of sleep, it is necessary to be clearly guided by the dynamics of its standards depending on age. Insomnia in children has a number of features compared to adults. Clinical variants of acute and chronic insomnia are associated with stress, childhood somatic pathology, and hyperactivation of the central nervous system. Children with concomitant neuropsychiatric pathology are prone to severe insomnia. The presence of negative associations of falling asleep in the first year of life contributes to the formation of insomnia in young children. In adolescents, insomnia is associated with sleep hygiene disorders and has a psychophysiological character. Treatment of insomnia in children includes normalization of sleep hygiene, the use of behavioral therapy methods, and prescribing pharmaceutical drugs with age restrictions. The safety profile plays a fundamental role in the drug therapy of childhood insomnia.