The most commonly recognized complications in cirrhotic patients include ascites, hepatic encephalopathy, variceal bleeding, susceptibility for infections, kidney dysfunction, and hepatocellular carcinoma; however, severe muscle wasting or sarcopenia are the most common and frequently unseen complications which negatively impact survival, quality of life, and response to stressor, such as infections and surgeries. At present, D'Amico stage classification, Child-Pugh, and MELD scores constitute the best tools to predict mortality in patients with cirrhosis; however, one of their main limitations is the lack of assessing the nutritional and functional status. Currently, numerous methods are available to evaluate the nutrition status of the cirrhotic patient; nevertheless, most of these techniques have limitations primarily because lack of objectivity, reproducibility, and prognosis discrimination. In this regard, an objective and reproducible technique, such as muscle mass quantification with cross-sectional imaging studies (computed tomography scan or magnetic resonance imaging) constitute an attractive index of nutritional status in cirrhosis. Sarcopenia is part of the frailty complex present in cirrhotic patients, resulting from cumulative declines across multiple physiologic systems and characterized by impaired functional capacity, decreased reserve, resistance to stressors, and predisposition to poor outcomes. In this review, we discuss the current accepted and new methods to evaluate prognosis in cirrhosis. Also, we analyze the current knowledge regarding incidence and clinical impact of malnutrition and sarcopenia in patients with cirrhosis and their impact after liver transplantation. Finally, we discuss existing and potential novel therapeutic approaches for malnutrition in cirrhosis, emphasizing the recognition of sarcopenia in an effort to reduced morbidity related and improved survival in cirrhosis.