Falls and mobility problems are two of the most common and serious concerns facing older adults. In addition to reducing function and causing considerable morbidity and mortality, falls and instability precipitate premature nursing home admissions. Impaired gait and balance, which rank among the most significant underlying causes of falls, are also common consequences of falls. Because older adults often do not report these problems to physicians, they may go undetected until after preventable injury and disabilities have occurred. Falls and mobility problems generally result from multiple, diverse, and interacting causes. After detecting a problem, clinicians must use careful and thorough diagnostic approaches to identify the most likely causes, contributing factors, and associated comorbid conditions, many of which will respond to intervention.