Objectives: to determine the prevalence of sleep deprivation among children, its causes, and parents’ awareness of the effects of sleep deprivation on their children’s health. Methods: A cross-sectional study was carried out among mothers in Medina, Kingdom of Saudi Arabia, from August till November 2016. Our study comprised all the mothers in Saudi Arabia raising children aged from 6 to 13 years old who agreed to participate. 2010 responses which were conveniently collected through self-administered semi structured questionnaire prepared by the researchers. Results: There is 44% of the sample following a regular schedule for sleeping and waking, while 49.6% of them is not. We noted that 74.9% of the sample of children sleep more than 5 hours in school nights compared to 70.4% of them who sleep the same duration in the night before the vacation or the weekend, but for the time to wake-up in the morning, we noted that 49.6% of them wake up at (4-6) am in regular nights compared to 11.5% of them who wake up at this time during the nights of the vacations. We found that 89.1% of them use computer, TV and video games, while only 10.9% of them don’t. Conclusion: About a quarter of Saudi children suffer from sleep deprivation. About half of Saudi children aren’t following regular schedule for sleeping and waking. There is a poor knowledge of parents regarding the effects of sleep deprivation on their children’s health. We recommend educating the parents about it, and teaching them how to overcome this problem.