Objectives There is limited guidance on how to effectively educate cancer survivors to adopt and maintain specific diet and physical activity recommendations, especially among underserved and under-resourced populations. Here, the objective is to present the development of a behavioral and theoretically-based multi-modal diet and physical activity intervention program for Hispanic/Latina breast cancer survivors, Mi Vida Saludable (My Healthy Life). Methods The development process was based on the 6 steps of the Nutrition Education DESIGN Procedure: (1). Decide behaviors; (2). Explore determinants; (3). Select theory-based model; (4). Indicate objectives; (5). Generate plans; and (6). Nail down evaluation. The theoretical framework for the intervention is Social Cognitive Theory. Results The resulting behavioral intervention consists of 2 components. The first component is in-person group education consisting of 4 lessons over 1 month. Each 4-hour group lesson includes a hands-on cooking component, a physical activity component, and facilitator-led nutrition education and discussion, with 2 field trips to a local grocery store and farmers’ market. The second component is an e-Health program that includes weekly text messages, biweekly emailed newsletters, and ongoing website access. Conclusion The systematic DESIGN Procedure provided practical guidance for developing a behaviorally-focused, theory-based, and culturally sensitive program that addresses both dietary and physical activity behaviors for delivery both in-person education and through eHealth. The Procedure may be useful for developing other behaviorally focused and theory-based interventions.