The purpose of this study was to provide an empirical measure of bedroom personalization and a descriptive characterization of the types of items included in a personalized space. The study compared the extent of personalization in three types of bedrooms, varying as to their homelike quality (private-homelike, private-institutional, and ward-institutional). A measure of the relative degree of personalization was obtained by recording the number of personal items for each room and dividing the number of items per room by each room's available vertical and horizontal surface area. The degree of personalization was found to be significantly greater in private-homelike rooms than in private-institutional or ward-institutional rooms. This study provides the first demonstration that personalization of a resident's bedroom can be quantified and opens the way for studies of factors contributing to the effect (e.g., facility regulations, family, and staff attitudes) and empirical studies of presumed consequences (e.g., resident satisfaction and improved functioning).