Malnutrition is one of the consequences of congestive heart failure and cardiac cachexia.It is a well-known unfavorable prognostic factor associated with increased mortality and a complicated postoperative course in cardiac surgery. The details of the development of cardiac cachexia determine the specific approach for nutritional care of such patients, including nutritional screening and assessment.There is no universally accepted approach to nutritional screening in cardiac surgery. However, existing evidence indicates that the Malnutrition Universal Screening Tool is the most appropriate. The components of the nutritional assessment of cardiac patients do differ significantly from those for other patient cohorts. Any dietary assessment method as well as anthropometric and laboratory data can be used for the nutritional assessment of cardiac patients. However, interpreting any single objective parameter is often challenging and must be supplemented with other criteria.Therefore, the nutritional assessment of cardiac patients has multiple components and should be performed in combination with the analysis of systemic inflammation.