The institution of marriage is in a state of great evolution, changing in response to rapidly shifting social values and norms. Indeed, even the definition of marriage is the subject of much heated social and political debate; it is one of the ‘hot button’ topics in both the scientific and lay press. In the context of such social transition, it is not at all surprising that there has been a rapid increase in relationship distress and dysfunction, evidenced by substantial increases in marital separations and divorce during the last century. Marital dysfunction manifests itself in a number of different ways and is very often marked by deficits in commitment to the relationship, low levels of mutual caring behaviors between the partners, problems with communication, and corrosive conflict resolutions skills. In turn, many dyads seek professional help to address the myriad of relationship problems in efforts to save their marriages in the context of multiple psychosocial pressures. In this chapter, a general description of marital dysfunction is provided. Additionally, a very commonly applied framework for understanding marital dysfunction, referred to as the ‘Seven Cs’, is described. Methods of relationship evaluation and assessment, including collection of communication samples, clinical interviewing, and use of self-report measures, are reviewed. An overview of empirically supported relationship intervention approaches is also provided, including a discussion of potential mechanisms of therapeutic action. Lastly, fundamental core and expert competencies for clinicians who provide relationship therapies are described, along with a brief description of the transition from basic competencies to expert.