Purpose of reviewThere is currently intense interest in understanding why certain elderly individuals become frail and disabled with age whereas others do not. Is frailty the result of an acceleration of normal aging processes or is it the result of chronic medical conditions that are superimposed on the conventional mechanisms of aging? The clinical problem of falls has long been recognized as a threat to some elderly individuals, but too often is not considered worthy of objective study. The factors underlying falls are now being investigated as part of the increasing attention being paid to the evolution of frailty in the elderly.Recent findingsFrailty in the elderly has been given many names, but increasing efforts are now being made to define frailty in a standardized way that would allow more objective study. The frail elderly patient usually shows loss of both neurological and muscle function. Falls in the elderly are an example in which deterioration may be present in both functions. Methods are being developed to separate the loss of muscle capacity from the associated loss of central and peripheral neurological function involved in gait and balance.SummaryThe definition of frailty has been centered around the onset of accelerated weight loss with an associated decrease of mass and strength of skeletal muscle. New studies are discussed that extend this definition. Methods for a more detailed analysis of the physiological and metabolic deficits leading to falls in the elderly may provide a better understanding of frailty in general.