BACKGROUND: Malnutrition is associated with clinical factors, including longer hospital stay, increased morbidity and mortality and hospital costs. OBJECTIVE: To investigate the prevalence of malnutrition using different nutritional indicators and to identify factors that contribute to malnutrition in hospitalized patients. METHODS: We investigated anthropometric, laboratory standards, nutritional risk screening (NRS), subjective global assessment (SGA), mini nutritional assessment and habitual energy consumption (HEC). Chi-square, Fisher’s exact test, Mann-Whitney test and univariate and multiple Cox regression analysis were used, at 5% significance level. RESULTS: It was found 21.01% of malnourished individuals by ASG; a total of 34.78% with nutritional risk according to NRS and 11.59% with low weight (BMI). There was no statistically significant difference in the prevalence of malnutrition by ASG (P=0.3344) and nutritional risk by NRS (P=0.2286), among the types of disorders. Patients with nutritional risk were of higher median age (64.5 vs 58.0 years; P=0.0246) and had lower median values of HEC (1362.1 kcal vs 1525 kcal, P=0.0030), of calf circumference (32.0 cm vs 33.5 cm, P=0.0405) of lymphocyte count (1176.5 cell/mm3 vs 1760.5 cell/ mm3, P=0.0095); and higher percentage of low body weight according to the BMI (22.9% vs 5.6%; P=0.0096). Lymphocyte count was associated with nutritional risk (P=0.0414; HR= 1.000; IC95%= 0.999; 1.000). CONCLUSION: NRS was more sensitive than other indicators in the diagnosis of malnutrition. Patients at risk were older and had lower HEC values, calf circumference, BMI and lymphocyte count. Low lymphocyte count was considered a factor associated with nutritional risk by the NRS.