Obstructive sleep-disordered breathing (SDB) is a common problem in children that may lead to growth failure, neurocognitive and behavioral abnormalities, cor pulmonale, and death. Primary snoring, upper airway resistance syndrome, and obstructive sleep apnea syndrome represent a spectrum of clinical manifestations accompanying increasing degrees of upper airway obstruction. Clearly, children with severe SDB need to be identified and treated promptly. Appropriate management strategies for milder forms of SDB are less clear. Some snoring children, for example, may have an increased frequency of obstructive apnea during sleep, with or without mild hypoxemia, but have essentially no daytime symptoms or apparent clinical consequences. Should these children be treated? If untreated, will these children eventually develop more severe obstructive SDB? Development of management strategies is hampered by the lack of data on the natural history of childhood SDB and on the correlation of specific polysomnographic abnormalities to symptoms and complications. In this review, we highlight recent information about the consequences of obstructive SDB in children, with particular emphasis on areas in which more data are needed.