Abstract Introduction Primary school children are more vulnerable to malnutrition; underweight or obesity. Continuous nutritional assessment of the vulnerable groups is very important for the evaluation of current health status, besides future planning for prevention and control programs. Aim of the Work To assess the nutritional status and body mass index among primary school children attending primary healthcare centre in 10th of Ramadan city, El Sharqia Governorate, Egypt, and to identify different demographic factors that can affect nutritional status among them. Materials and Methods A cross-sectional study was conducted among 60 randomly selected primary school children. An interview questionnaire was used to collect data including demographic characteristics, family history of obesity, food intake using food frequency formula and the pyramid of food servings. Anthropometric characteristics including weight, height and BMI was estimated. Results The age ranged (6-12) for males and (6-9) for females, the mean was 8.62 and SD was 1.69. The mean height and weight of studied children were 127.33 ± 11.20 cm and 36.23 ± 13.74 kg respectively. Most of them had normal current weight (41.7%) and normal birth weight (86.7%). Overweight and obese represent 8.3% and 16.7% respectively, while underweighted children represent 33.3%. BMI was associated with child age, family opinion in child weight, birth weight and family history of obesity. Most of studied children took sufficient amount of animal protein, while consuming grains & carbohydrates, beans, vegetables, fruits and fats 4-6 times per week. 80.0% consume sweets & processed sugar 4-6 times per week. Consumption of junk foods and soft drinks and juices was high (66.7% for each) 4-6 times per week. Diet was statistically associated with BMI (frequency and standard requirements); overweight and obese children took carbohydrates & grains, soft drinks &juices and junk foods in amounts that above the standard requirements and in higher frequency compared to underweight and normal weight children (≥4 times per week). The consumption of vegetables and fruits was not related to BMI as most of participated children took them at the standard requirement. Conclusion and recommendations The prevalence of malnutrition disorder (underweight and obesity) among primary school children in 10th of Ramadan City is considerable. High BMI was associated with high frequency of eating carbohydrates& grains, soft drinks & juices, fats and junk foods and their daily requirements. Low BMI in underweight children not related to significant type of food as they mainly took their standard requirements in frequency around 4 times per week. Feasible and effective nutritional and educational programs for primary school children must consider child characteristics and eating habits.