Background & Aims: Early detection of nutritional status in pregnancy is important to ensure healthy outcomes for pregnant women and children. Several malnutrition screening tools were recommended to be used in pregnant women. Thus, the purpose of this study was to validate the International Federation of Gynecology and Obstetrics (FIGO) Nutrition Checklist and Obstetric Nutritional Risk Screening (NRS) by comparing their results with the reference standards. Methods: The two screening tools (FIGO Nutrition Checklist and obstetric NRS) were performed on 200 pregnant women at the National Hospital of Obstetrics and Gynecology. The validity of the two screening tools was assessed by (1) comparison with a composite diagnostic criteria; (2) comparison with Estimated Fetal Weight (EFW). The anthropometric (weight, height, and mid-upper arm circumference), 24-h dietary recall, EFW, hemoglobin, and serum albumin were measured. Cohen's κ-statistics, sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC) were computed. Results: FIGO and NRS identified 21.5% and 15.5% of the pregnant women as being at risk of malnutrition, respectively. Based on the composite diagnostic criteria, 13.5% of the pregnant women were confirmed to be malnourished. When compared with composite diagnostic criteria, FIGO had a numerically lower specificity (87.28% vs 94.22%) and a numerically lower agreement (κ: 0.52 vs 0.68) than NRS but FIGO demonstrated a similar sensitivity (77.78%) and a similar AUC (0.825 vs 0.860) to NRS. Using EFW as a reference standard, FIGO had higher sensitivity (61.11% vs 55.56%) and a similar AUC to NRS (0.718 vs 0.720), but FIGO showed a numerically lower specificity (82.42% vs 88.46%) and a numerically lower agreement (κ: 0.27 vs 0.33) than NRS. Conclusion: This study supports the use of the FIGO nutrition checklist and obstetric NRS to identify risk of malnutrition in hospitalized pregnant women. These findings highlight the potential for these tools to be adapted for use in other healthcare systems and countries facing similar challenges in maternal nutrition assessment, particularly in resource-constrained settings.