Walking may appear to be a simple motor task, but is in fact a very complex behavior that involves virtually all levels of the nervous system. In daily clinical practice, subtle gait changes are commonly observed as we grow older, and these are often attributed to aging itself (the term “senile gait” was coined for this). However, growing evidence suggests that such age-related gait changes should not be regarded as a mere consequence of aging, but rather as indicators of underlying age-related disease. Numerous studies have shown that gait changes can be present for years during an otherwise prodromal phase of many progressive neurological disorders. As such, gait changes serve as clinical biomarkers of disease-related dysfunction in the neurological structures involved in gait control. We elaborate on the potential for gait to be exploited as an early warning system for underlying pathology. We also discuss the importance of such a proactive approach: an earlier diagnosis can lead to timely installment of symptomatic support, and sometimes start of prophylactic treatment. This can help reduce disability, and possibly increase survival because age-related gait disturbances are associated with increased mortality in the general population.