Proper nutrition is essential for enhancing healthcare outcomes. Elevated rates of malnutrition are present in hospitalized patients. Malnutrition and unmet nutritional needs increase morbidity and mortality, lower quality of life, lengthen the time spent on mechanical ventilation, and lengthen hospital stays, all of which raise the expense of medical treatment. Patients who are critically ill need specific care to minimize muscle wasting, avoid overfeeding, and prevent complications from nutritional therapy. The purpose of this research is to review the available information about identification, prevention, and management of malnutrition in the critically ill patients. To identify patients who are more likely to experience complications from malnutrition, nutritional status is evaluated. Various assessment methods and tools are present to identify malnutrition in critically ill patients. Effective targeting of appropriate nutrient levels, and prompt initiation of nutritional support, among other measures can reduce the risk of malnutrition. Ideally, enteral nutrition should be started after initial 24 to 48 hours. Parenteral nutrition may be employed if the nutritional need is not properly supplied by enteral nutrition even after seven days following intensive care admission. In patients receiving nutrition therapy, electrolytes should be carefully assessed. Even if 50% to 60% of nutritional requirements are not successfully met during 72 hours of oral nutrition support then tube feeding should be considered. Further clinical research can be beneficial in determining the effectiveness and outcomes of nutritional therapy in malnourished critically ill patients.