Background: Fully nutrition support for patients in developing countries like Vietnam is challenging. Aim: To estimate the prevalence of patients with nutritional risk at admission and describe feeding regimen of critically ill patients in a suburban hospital in Hanoi, Vietnam. Methods: An observational study was conducted among 154 patients at department of Intensive Care Unit (ICU). The Nutrition Risk Screening 2002 (NRS2002) and Modified Nutrition Risk in Critically Ill (mNUTRIC) were used for screening nutritional risk at admission. Body Mass Index (BMI), Mild-Upper Arm Circumference (MUAC), and personal information were recorded. The feeding regimen of patients was monitored from the first to seventh day. Results: the patients were aged 66.5 ± 15.4 years, with an APACHEII of 13.0 ± 5.5 and SOFA 3.1 ± 2.6: 47.4% were malnutrition by MUAC, 16.2% had a severely low BMI (<17.8), 20.8% had low BMI (17.8 to <20). According to NRS2002 and mNUTRIC, the prevalence of patients with high nutritional risk was 53.9% and 13%, respectively. The proportion of patients receiving less than 25 kcal/kg/day was 84%, 60%, and 47% on the first, the fifth, and the seventh day. Protein intake below 1.3 g/kg/day was 50% on the seventh day. Up to 27.4% of patients had no nutrition support on the first day. Conclusions: ICU patients had nutritional risk with high rate. The feeding regimen for patients achieved a progressive energy and protein intake over the first 7 days.