Background: Malnutrition is an underlying factor in many diseases in both children and adults, and it contributes greatly to the disability-adjusted life years worldwide. It is a major public health concern in developing countries among children since it places a heavy burden on already disadvantaged communities. Methods: This is systematic review was carried out, including PubMed, Google Scholar, and EBSCO using the following terms in different combinations: Malnutrition, overweight, underweight, systemic review, primary school children, Saudi Arabia. Results: The review included 9 studies from different countries that assess the level of malnutrition and associated factors among school children. Many of studies reported high prevalence of malnutrition among school children which included overweight, stunting, wasting and underweight. The studies reported that age, gender, regularity of father’s employment, and dietary factors were associated with malnutrition. Also, the type of school attended was found to be associated with malnutrition. Conclusion: This review concluded that there was high malnutrition prevalence among school children in different parts and its affected by many factors like age and gender.