The quality of marital relationships is the most studied topic pertaining to marriage and family life. Moreover, clinicians have become increasingly interested in this variable as divorce rates have climbed and as services for counseling and therapy have become more readily available and more widely accepted. These research and clinical needs necessitate the availability of measures of variables which assess marital quality (e.g., marital adjustment, satisfaction, and happiness). This article discusses the need for such measures, reviews the history of measurements in this area, identifies some conceptual and methodological issues of relevance, and then focuses most specifically on the Dyadic Adjustment Scale developed by Spanier. Some cautions for clinicians are noted, and a discussion of future measurement needs is presented.