Malnutrition often occurs in patients with disabilities. The prevalence of malnutrition in geriatric rehabilitation was higher than in hospital (50.5% vs 38.7%) according to MNA classification. Nutrition care management of patients with disabilities is often inappropriate. As nutritional status is associated with rehabilitation outcome, a combination of both rehabilitation and nutrition care management may be associated with a better outcome. This concept is defined as rehabilitation nutrition. Rehabilitation nutrition aims to assess patients according to the International Classification of Functioning, Disability and Health including nutrition status and to practice a rehabilitation nutrition care plan under adequate prognosis prediction. It is not enough for patients with disabilities to coordinate only their rehabilitation or clinical nutrition. Rehabilitation nutrition care management is important to improve their activities of daily living and quality of life. Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength. Primary sarcopenia is considered to be age-related when no other cause is evident, other than ageing itself. Secondary sarcopenia should be considered when one or more other causes are evident, such as activity-related sarcopenia, disease-related sarcopenia, or nutrition-related sarcopenia. Activity-related sarcopenia can result from bed rest, deconditioning, or zero-gravity conditions. Disease-related sarcopenia is associated with invasion (acute inflammatory diseases), cachexia (cancer, advanced organ failure, collagen diseases, etc.), and neuromuscular disease. Nutrition-related sarcopenia results from inadequate dietary intake of energy and/or protein. Treatment, including rehabilitation and nutrition care management, differs according to the causes of sarcopenia. No nutrition care, no rehabilitation. Nutrition is a vital sign for rehabilitation.