BACKGROUND: Malnutrition is associated with increased hospital stay and subsequently higher healthcare costs. Early detection of malnutrition among people accessing health services at public hospitals is vital to identify and treat malnutrition effectively and in a timewise and cost-effective manner. The aim of this study was to evaluate the nutrition risk of this population.MATERIALS AND METHODS: Nutrition screening was performed for 2970 patients (52% male; 55.3 ± 20.1 years old) at 34 hospitals. Nutrition risk was evaluated through 3 nutrition screening tools-Nutritional Risk Screening 2002 (NRS-2002), Malnutrition Universal Screening Tool (MUST), and Mini Nutritional Assessment-Screening Form (MNA-SF).RESULTS: Malnutrition risk was found: 25.3% with NRS-2002, 22.9% with MUST, and 60.5% with MNA-SF. Nutrition risk among patients accessing health services at public hospitals increases with age (high-risk patients among those ≥80 years old: NRS-2002, 9.8%; MUST, 16.9%; MNA-SF, 43.9%). The highest prevalence of nutrition risk was found at the oncology departments (16.7%, NRS-2002; 23.4%, MUST). According to the NRS-2002 and MUST, surgical patients have a greater risk for malnutrition vs internal medicine patients (adjusted odds ratio [OR] = 1.0, P < .001; adjusted OR = 1.17, P < .001, respectively), whereas according to MNA-SF, surgical patients have 30% lower probability for malnutrition risk against internal medicine patients (adjusted OR = 0.7, P < .001).CONCLUSIONS: A high prevalence of malnutrition risk was reported among patients accessing health services at public hospitals. Early detection of malnutrition is vital to allow the allocation of the needed workforce to manage it effectively.