Hospitalization stress is a reaction that children face in a new setting during the hospital care process. Children admitted to hospital face a crisis in improving their health and environmental status. The purpose of this study is to establish the relationship between hospitalization and stress levels in school-aged children in the hospital room. The study was performed in January-February 2020 at Koja North Jakarta Hospital, with 78 respondents. The research method is a descriptive association with a cross-section approach. Data collection using the DAS (Depression Anxiety Stress Scales) questionnaire. The findings revealed that of the 78 respondents, there were 13 children with mild stress (16.7%), 51 children with moderate stress (65.4%) and 14 children with high stress (17.9%) during hospitalization. Results of statistical analyses using chi-square and Kendal tau C showed a relationship between gender (p-value 0.025) and duration of stay (p-value 0.013) and child stress levels during hospitalization. There was no association between the experience of being treated with stress during hospitalization (p-value 0.562). The level of stress in children during hospitalization is affected by gender and duration of stay.