The purpose of this study is to assess the development, current states, and problems of MEDLIS document delivery service. With the analysis of MEDLIS transaction data from 2001 to 2011, we identified continuous usage decrease, unbalanced contribution by type of institution, high dependence on back issues, use differences among subfields of medicine, relatively low success rate, and various reasons for failure. Based on the results, recommendations for the maintenance of union catalog database, technical support for search capability enhancements, establishment of back issue archiving policy, user training and publicity, and membership expansion are suggested to promote the service.