Understanding the role of the built environment on physical activity behavior among older adults is an important public health goal, but evaluating these relationships remains complicated due to the difficulty of measuring specific attributes of the environment. As a result, there is conflicting evidence regarding the association between perceived and objectively measured walkability and physical activity among urban-dwelling older adults. This suggests that both actual environmental features and perceptions of these attributes influence walking behavior. The purpose of this pilot project is to create an Objective Walkability Index (OWI) by census block using a Geographic Information System (GIS) and supplement the results with resident perceptions thus more accurately characterizing the context of walkability. Computerized Neighborhood Environment Tracking (ComNET) was used to systematically assess environmental risks impacting activity patterns of older adults in two New York City neighborhoods. In addition, the Senior Center Evaluation of the Neighborhood Environment (SCENE) survey was administered to older adults attending two senior centers located within the target neighborhoods. The results indicate that there is substantial variation in OWI score both between and within the neighborhoods suggesting that residence in some communities may increase the risk of inactivity among older adults. Also, low walkability census blocks were clustered within each neighborhood providing an opportunity for targeted investigation into localized threats to walkability. A lack of consensus regarding the association between the built environment and physical activity among older adults is a consequence of the problems inherent in measuring these determinants. Further empirical evidence evaluating the complex relationships between the built environment and physical activity is an essential step towards creating active communities.