With training that emphasizes relationship systems, marriage and family therapists are uniquely attuned to interpersonal dynamics, interdependence, and the influence of relationships on individuals’ perceptions, beliefs, and attitudes. While recent statistical advances have contributed to a proliferation of resources designed to introduce researchers to dyadic data analysis, guidelines related to the methodological aspects of dyadic research design have received less attention. Given the potential advantages of dyadic designs for examining couple and family relational and therapeutic processes, the purpose of this article is to introduce marriage and family therapy researchers to dyadic research methodology. Using examples from our own research, we discuss methodological considerations and lessons learned related to sampling, measurement, data collection, and ethics. Recommendations for future dyadic research are provided.