This review focuses on the most current information on the pathogenesis, diagnosis and treatment of sarcopenia and malnutrition in patients with liver disease. Sarcopenia and malnutrition are common complications of liver diseases. Liver cirrhosis, as a stage of the pathological process, serves as the main predisposing factor for the development of malnutrition and sarcopenia. The frequency of sarcopenia in liver cirrhosis is 30–50% and reaches 100% in decompensated patients. The main pathogenetic links are: impaired proteostasis of skeletal muscles, systemic inflammation and changes in gut microbiota. In recent years, enough data have been accumulated to consider these conditions as a prognostically unfavorable factor in patients with liver cirrhosis of various etiologies, affecting their quality of life and survival, as well as worsening the out-comes of transplantation. This dictates the necessity to define unified approaches to diagnostics and correction of these conditions. Currently, tests are used for diagnosis, which allow to assess muscle strength and function. Muscle mass is assessed using instrumental methods by measuring individual muscles and calculating skeletal muscle indices. In patients with liver cirrhosis and concomitant sarcopenia and malnutrition, nutritional and lifestyle modification strategies are applicable for correction in addition to therapy aimed at elimination of the etiologic factor. The aim of the review is to evaluate the problems of diagnosis and effective treatment of malnutrition and sarcopenia in patients with liver disease based on literature data. The article presents an overview of the main strategies for the approach, diagnosis and correction of these conditions.