Many children experience some type of sleep problem. Often, these are transient problems with no long-lasting sequelae. But in certain cases, sleep problems may significantly impact on functioning and well-being. Sleep disorders in children can be classified into two major categories. Dyssomnias include those disorders that result in difficulty either initiating or maintaining sleep or involve excessive sleepiness. Parasomnias are disorders that disrupt sleep after it has been initiated but do not result in complaints of insomnia or excessive sleepiness. Even though sleep disorders in children are common, not enough is known. This article reviews the dyssomnias and parasomnias experienced by children, discusses methodological limitations of the studies reviewed, and presents future directions for research in this field.