This article examines the important role that the interplay between theory, research, and application has in fostering breakthroughs in the treatment of clinical problems. This issue is presented in the context of an ongoing program of psychotherapy research that targets for intervention Hispanic behavior problem youth and their families. Findings and breakthroughs in structural family therapy, the measurement of family and child psychodynamic functioning, the development of culturally appropriate interventions, the role of attrition as a measure of outcome, and the investigation of theoretically postulated mechanisms in behavior change are discussed. Recommendations for future research directions are made.