The NCI Standardized Surveys of Walking & Bicycling Database contains survey questions and a list of validation studies for standardized survey questions concerning walking and biking from multiple national and international physical activity surveys and questionnaires (PAQs). The purpose of this database is to provide easy access to a large number of questions assessing duration and frequency of walking and bicycling in the non-disabled adult population. The results of validation studies identified for some of the PAQs are briefly reviewed.