Material-method The research was conducted on 999 patient 2–6 years presenting patient out-patient clinic. Parents were given a survey containing questions about the sociodemographic and sleep.

Results 30.9% of children were entering to bed in the hours 20.00 to 22.00 and 67.0% of children were entering to bed in the hours 22.00 to 00.00. Sleeping and waking hours of children were found to be compatible with their parents (p=0.001). 50.2% of children with bedtime from 20.00 to 22.00 were fall asleep immediately and 22.6% of children with bedtime from 22.00 to 00.00 were fall asleep immediately (p=0.001).We found that 62.9% of children snoring, 72.5% of children with mouth breathing, 38.7% of the children stopped breathing, 79.3% of the children were restless sleep, 80.2% of children saw a nightmare, 43.1% of the children gnashed teeth during the sleep. We found that snoring, mouth breathing were more than and sleeping hours were later for son children and nightmares were more frequent in girls (p<0.05). We found that snoring, mouth breathing, restless sleep and frequent waking findings were more frequent in children with symptoms of attention deficit hyperactivity than in the other group.

Conclusions In the preschool-aged children, sleep disorders were common in. Sleep disorders were more frequent in children with hyperactivity symptoms. Primary care assessment of preschool-aged children should be questioned their sleep problems.