OBJECTIVES: To validate a modified Subjective Global Nutritional Assessment (mSGNA) for assessing nutritional status among Vietnamese children. STUDY DESIGN: A cross-sectional study was conducted at the National Children's Hospital in Vietnam, where 200 children were assessed using mSGNA, Subjective Global Nutritional Assessment (SGNA), and a standardized method developed by the Academy of Nutrition and Dietetics (AND) and the American Society for Parenteral and Enteral Nutrition (ASPEN). RESULTS: The mSGNA showed high accuracy with 82.9 % sensitivity and 90.8 % specificity when compared to SGNA, and moderate accuracy (72.0 % sensitivity, 77.3 % specificity) against AND/ASPEN. The kappa value for mSGNA-SGNA agreement was 0.8 (95 % CI 0.686-0.849), indicating substantial agreement, while the kappa value for mSGNA-AND/ASPEN agreement was 0.5 (95%CI 0.304-0.567), reflecting moderate agreement. CONCLUSIONS: The results suggest that mSGNA is a reliable tool for identifying malnutrition in Vietnamese pediatric patients, with high sensitivity and specificity in comparison to SGNA and moderate effectiveness against AND/ASPEN standards.