Malnutrition, overweight, and obesity are growing issues among primary school-aged children in Vietnam, with rising rates of obesity and unhealthy eating behaviors, highlighting the need for effective nutrition education programs. Therefore, the study aims to examine the effectiveness of nutrition education on the eating behavior and anthropometric indices among students at two primary schools, in Nam Dinh city, Vietnam in 2024. Methods: A quasi-experimental study was conducted with 600 students (300 in the intervention group and 300 in the control group), aged 6-11, at two primary schools in Nam Dinh city. A nutrition education program, led by trained teachers, was implemented over two months, with 7–15-minute sessions each week during class activities, science lessons, and lunch breaks. Additionally, before mealtimes, the homeroom teacher guides the children on food choices and dishes, encourages them to eat vegetables, enjoy a variety of foods, and limit unhealthy options. Data on eating behavior and anthropometric index were collected at baseline and two months after the intervention. Results: After the 2-month intervention, there was a statistically significant improvement in the nutritional practices of participants in the intervention group compared to the control group (P<0.05). However, no statistically significant differences were found in anthropometric indices (Weight and Height) between the two groups at both pre- and post-intervention time points (P<0.05). Conclusions: The school-based nutrition education program was effective in improving students' eating behavior. Schools should implement and expand nutrition education programs to promote healthier eating behaviors among students.