This study was to assess the physical and psychological wellbeing of elementary school children and to explore the determinant factors of psychological and physical wellbeing of elementary school children in Repi primary school. Respondents, were recruited from one randomly selected school in Kolfa Keranio Sub-city of Addis Ababa, The participants were: 220 elementary school children (9 to 12 years old). Respondents were selected using simple stratified technique. A demographic questionnaire, a psychological wellbeing scale and physical wellbeing scale was employed to collect data. Quantitative methods of data analysis methods such as percentages, mean, t-test, and Analysis of Variance (ANOVA) were employed to analyze the data. The results of the study revealed that using mean value of the psychological and physical wellbeing scale, children physical and psychological wellbeing is low. On the other hand, ANOVA showed that there is statistically significant difference among children mother’s educational levels in terms of on psychological and physical wellbeing. Furthermore, the result of post Hoc comparison revealed a significant mean difference only between mothers’ educational background in Primary and Tertiary level. The study concludes that majority of the elementary school children in the study site had low on psychological and physical wellbeing. Counseling and Child Psychology should be taught to teachers and health care providers, giving considerations to the areas when building school equality important to the class room and learning materials to protect the physical wellbeing and safety of children