This research was carried out to examine the sleeping habits of children who are hospitalized and have chronic diseases. The study has been conducted with 360 children who were hospitalized for at least one week in the pediatric clinics of a university hospital between January 1, 2019 and May 31, 2019. In the research ‘Child Information Form’ and ‘Child Sleep Habits Survey’ have been used. The data have been assessed in computer environment by using percentage distributions, means, t test and correlation. It has been determined that, of the children included in the study; 46.9% were girls, 53.1% were boys and the mean age was 7.52 ± 4.22. It has been detected that; 68.6% of children had previously been hospitalized, 45.6% had chronic disease and 95.8% had sleep problems. Among the children who participated in the study, a significant difference has been determined between previous hospitalization and having chronic disease, and sleep habits sub-dimensions and sleep habits total scores (p <0.05). It has been found that there was a negative correlation between the age of the children and bedtime, sleep anxiety, night awakening, sleep habits total scores, and there was a positive correlation between the hospitalization days and delayed sleep, parasomnia, sleepiness during the day and sleep habits total scores. It has been determined that hospitalized children with chronic diseases may have sleep problems. It has been detected that the children’s previous hospital experience and the states of having chronic illness may affect sleep habits. Accordingly, the pediatric nurses are recommended to provide education and counseling according to the sleeping needs of hospitalized children.