Objectives: This study was conducted to investigate 3-6 age group children's sleep habits andaffecting factors. Materials and Methods: This descriptive study was conducted with 189 mothers who have 3-6 year old children hospitalized in pediatric clinic in a üniversity hospital. The research data was collected "Questionnaire Form" consisting of socio-demographic characteristics questions regarding of the family and child's sleep habits. Data were analyzed by percentage, mean and standard deviation and chi-square test. Results: The mean age of the children was 4.3±1.0, and 30.7% had a chronic illness. Children were sleeping average 9.7±1.4 hours at night and were going to sleep at 21.9±1.05 hours on the weekdays, at 22.24 ± 1.06 on the weekends. Half of the children (42.3%) was sleeping on their own, 24.3% of them with their mother, 11.6% of children was sleeping with mother in the same bed, 10.1% in the same bed both mother and father. It was determined that 37.1% of children need an object for sleeping, 69.5% of this toy and 14.5% of children touching the mom during sleep. 10.6% of children have difficulty with falling asleep, 29.1% was bed- wetting, 20.6% was nightmares. İt was expressed by mothers when their children sleep less there was seeing irritability/anger 49.7% of children, 43.4% crying of children. There was a statistically significant difference between children ages with sleep in the daytime and where they sleep. Three-four year-olds were more sleeping in the daytime and in the same room with their mother. Conclusion: In this study, it was determined that the children sleep hours are late and less, suffer from various sleep problems and some of the children were sleep in the same room with their parents and in the same bed