Qualitative methods were used to develop a contextually relevant quantitative measure of parenting stress and inform the design of family-focused interventions aimed at preventing adolescent mental and behavioral health problems. The study focused on the experiences of low-income one- and two-parent families representing three ethnic groups (Mexican, African, and European Americans) living in low-income neighborhoods in a large Southwestern city. This report describes the place of this study in a broader program of prevention research, the qualitative methods and data analysis procedures employed, and how the results were used to develop a new measure of parenting stress and inform future program design. The report also includes reflective comments on the methods used and lessons gained.