Introduction: Malnutrition adversely affects clinical outcome of hospitalized patients. This observational prospective study was done to assess the prevalence of malnutrition and its grade among patients admitted in a mixed intensive care unit (ICU) of a tertiary care hospital in order to help devise a comprehensive nutrition program for the malnourished. Materials and Methods: A total of 500 sequential patients admitted to the ICU were screened on admission over a year period for malnutrition using the Subjective Global Nutritional Assessment (SGNA) score. Distribution of the degree of malnutrition according to co-morbidities was also documented. Results: Of the total, 198 (39.6%) patients were malnourished, including one patient qualifying as severely malnourished; 68% patients were male, however, there was no statistically significant difference between nutrition status between sexes. Hypertension, diabetes, and cancer were the three most commonly encountered co-morbidities among the malnourished. A total of 86% of all cancer patients admitted were malnourished against only 12% of trauma patients. Conclusion: This study showed that almost two-fifth of the patients admitted were malnourished in this tertiary care hospital and that there is an urgent need to develop a comprehensive nutritional care program in many such Indian ICUs.