Screening for malnutrition is recommended for all hospitalized patients and can be performed using tools such NRS-2002, MUST, and MNA-SF. Patients at risk should undergo further evaluation for the diagnosis of malnutrition using a validated tool, including the GLIM criteria. This study aimed to evaluate the prevalence of malnutrition and its risk at hospital admission in Internal Medicine Wards, and to assess the impact of malnutrition on the length of stay and on the development of infectious complications.