Sarcopenia and frailty are both highly relevant entities with regard to functionality and independence in the elderly. The term sarcopenia has been introduced already in the late 80s and since then attracted the interest of many researchers, the majority being interested in its pathophysiology. Nevertheless there is still no consensus on the definition of sarcopenia and its diagnosis. Despite its relevance for functionality and autonomy most clinicians caring for the elderly are not familiar with sarcopenia and it has not become part of the routine geriatric evaluation. The concept of frailty has recently been supported by the introduction of two new working definitions. Since then clinical research on frailty has steeply increased. The influence of frailty on different age-associated diseases has been investigated and populations at risk for complications of medical or operative therapy are identified with the help of this concept. Simultaneously the pathophysiologic mechanisms involved in the development of frailty are explored. While sarcopenia may be regarded as a clinical sign that is not specific for the elderly, frailty may be seen as a multidimensional geriatric syndrome which implies a greater relevance for the clinician than the one dimensional approach of sarcopenia.