Background: Nutrition is the real determinant of human health. The development of children into healthy adults is dependent on their growth, in a healthy environment and having balanced nutrition. Objective: (1) To determine the association of nutritional status of children with their age, sex and socioeconomic status. (2) To compare the nutritional status of government school children and private school children. Study Design: Comparative cross-sectional. Settings: Study was conducted in two schools of Faisalabad, Pakistan. Government Girls high school, Punjab Medical College (PMC), Colony Faisalabad and The Smart School, Faisalabad. Duration: Eight months from Jan 01, 2020 – Aug 30, 2020. Methodology: The study was conducted on 200 children, including males & females, to compare weights and heights among government (government) and private (private) schools. Age groups ranging from 9 above to 14 years were being studied. The data was collected by taking anthropometric measures, height and weight, of the students. To assess the nutritional status, the anthropometric measurement of WHO 2007 reference was used as Weight for Age Z-score (WAZ), Height for Age Z-score (HAZ) and Body Mass Index (BMI) for Age Z-score (BAZ). Descriptive statistics and Pearson’s correlation test were used for statistical analysis. Data was analyzed statistically by using SPSS version 20. Results: The weight of private school children (39.3400 ± 2.39199) was normal as they have adequate diet as compared to government school children (38.7500 ± 1.43812) while 2% children were over weighted. Height of private school children (147.7600 ± 5.04949) was more as compared to government school children (146.8100 ± 4.34310). Statistically Pearson Correlation between weight of private and government school’s children was highly significant, p=0.000, df= 1, CI= 95%. Demographic information with height and weight of the children were taken. Z-score was calculated and graphs were plotted. A value within ± 2 SD in these graphs was considered as normal. Conclusion: Socio-economic status affects the availability and quality of food. For under-weight Children, unhygienic and low-quality food/stuffs are the major contributing factors.