Breast cancer is the most common cancer among Latina women, and Latina women are at higher risk for breast cancer mortality than white women. Lifestyle factors, such as consuming a nutritious diet and engaging in regular physical activity, promote health and are protective against heart disease, type 2 diabetes, and breast cancer recurrence. Previous studies have developed and tested interventions for Latina breast cancer survivors to improve diet and increase physical activity, however, no studies to date have developed a smartphone delivered intervention. The purpose of the current study was to compare two Smartphone delivered interventions, My Health, which focused on diet and physical activity, and My Guide, which focused on psychosocial functioning, on dietary and physical activity outcomes, post-intervention, and at a 2-week follow-up assessment. Overall, participants receiving the My Health intervention reported a greater reduction in daily fat sources than the My Guide group over time. However, daily sources of fat did not differ between conditions. Walking, measured by estimated weekly metabolic equivalents, increased across time points in both groups. These preliminary findings suggest that eHealth interventions aimed at improving lifestyle factors may favorably impact nutritional intake and physical activity. Future research should utilize more comprehensive and objective measures of diet and physical activity, and incorporate more behavioral lifestyle components into the intervention in larger samples with a longer follow-up period.