This chapter introduces RELATionship Evaluation Questionnaire (RELATE) as a relationship assessment instrument by providing an overview of the theoretical foundation and history upon which it is based, to describe its scales and subscales, and to review its contribution to empirical literature. It also provides a guide to the ways RELATE is used by the lay respondent, the applied professional, and to the research professional. RELATE information was disseminated primarily through traditional academic avenues such as peer-reviewed journals, books, and conferences. The RELATE Institute remains dedicated to the development and testing of a framework of healthy premarital and early marital relationships. There are four relationship contexts that are explored in RELATE: the individual, the family, the cultural, and the couple. The RELATE questionnaire contains over 270 items that make up more than 60 scales and subscales. The objectives of RELATE fit the needs of many applied programs.