Sleep is critical to brain health at any age, but especially for the high-risk newborn. Protecting it is a challenge in the NICU for many reasons - babies are almost always asleep, it is difficult to tell what stage of sleep they are in, and many sources of sleep disruption in the NICU are not entirely preventable. Sleep usually occurs as part of a circadian rhythm at other ages, but high-risk newborns do not exhibit circadian rhythmicity and the NICU environment is not conducive to developing one. Both structural and operational strategies to protect sleep and its beneficial effects on the brain are outlined. Increased parental interaction with the baby may be the best way to reduce noxious stimuli and provide nurturing stimuli while supporting sleep. (C) 2015 Elsevier Inc. All rights reserved.