context: the investigation of risk factors associated with nutritional status could contribute for better knowledge of the malnutrition. objective: to investigate the incidence of malnutrition and its possible association with many parameters that assess nutritional status and to identify the associated risk factors. methods: the nutritional status was assessed in 235 hospitalized patients. malnutrition was defined as present when the patient presented at least two anthropometric criteria below the normal range and habitual energy intake below 75% of the energy requirement (hei/er<75%). gender, age, type of disease, recent weight change and dental problems were investigated as possible associated risk factors. the chi-square and mann-whitney tests were used to compare the data and univariate and multiple logistic regressions were used to identify the factors associated with malnutrition. the odds ratio (or) and confidence interval (ci) of 95% were calculated with the significance level set at 5% (p<0.05). results: one-fifth (20%) of the patients were malnourished on admission to the hospital and 27.5% reported recent weight loss. malnutrition (p<0.0001) was greater in patients with malignant diseases. the only variables significantly associated with malnutrition according to univariate logistic regression were recent weight loss (p = 0.0058; or = 2.909; ic95% = 1.362; 6.212) and malignant disease (p = 0.0001; or = 3.847; ic95% = 1.948; 7.597). when multiple regression was used in the model which included type of disease, malignant disease was shown to increase the chance of malnutrition fourfold (p = 0.0002; or = 3.855; ic95% = 1.914; 7.766). when disease was excluded, recent weight loss also increased malnutrition fourfold (p = 0.0012; or = 3.716; ic95% = 1.677; 8.236). conclusion: patients with a history of recent weight loss and those with malignant diseases are more susceptible to malnutrition.