Malnutrition is still a largely unrecognized problem in hospitals. Malnutrition in hospitalized patients is generally related to increasing morbidity and mortality, and costs and length of stay. The aim of this study was to assess the nutritional status of patients on admission to a general hospital using different nutritional scores and to test the sensitivity and specificity of these scores. Sample population included 60 patients (55% male; 45% female) selected (aged 65.6+/-15.9 y) at random by using a computer software program. The nutritional state assessment was performed within 48 h of admission, using different nutritional indices (Subjective Global Assessment (SGA), Nutritional Risk Index (NRI), Gassull classification, Instant Nutritional Assessment (INA) and a combined index). About 78.3% of patients were found to be malnourished on admission. The frequency of malnutrition degree varied from 63.3% as assessed by the SGA to 90% with the NRI. Malnutrition severity was not related to the diagnosis. However, an elderly population was associated with a higher prevalence of malnutrition. INA was the best single score to identify patients who are malnourished or at risk of malnutrition and who may benefit from nutrition support.