Older drivers tend to be involved in more severe crashes compared to middle-aged drivers, and U.S. Census Population statistics indicate that the older-driver population is rapidly increasing. Therefore, an improvement in older-driver safety is both important and necessary. In this analysis, a statistical modeling technique was used to identify factors contributing to older-driver injury severity. Two separate models were developed for rural and urban locations, which incorporated several potential explanatory variables. Speed, gender, presence of passengers, road type and street-lighting conditions were found to be important factors affecting injury severity of older drivers on both rural and urban roads.