African American breast cancer (AA BC) survivors are more likely to have cancer-related comorbidities compared with other women, ultimately putting them at higher risk for overall mortality and breast cancer-specific mortality. Survivorship care guidelines emphasize the importance of attention to obesity, weight management, and physical activity. Mobile technologies have been effective for improving health behaviors among cancer survivors, though few studies have focused on AA BC survivors. Creating Healthy Actions through Technology (CHAT) was a 4-week pilot intervention that employed an ecological momentary assessment (EMA) to improve survivors’ physical activity and diet behaviors. We evaluated the acceptability, feasibility, and impact of a mHealth intervention for AA BC survivors. Participants (N = 22) were randomized to intervention (n = 13) or control (n = 9). All participants completed daily EMAs via smartphone for 4 weeks and wore accelerometers for seven consecutive days at baseline, 4, and 8 weeks. Intervention participants additionally received tailored health messages. Diet was measured using a self-reported questionnaire and physical activity with accelerometers. Participant engagement was high. Of 84 EMA assessments, the average response was 63 (SD 16.1). Participant accelerometer wear was at least 6 of the 7 days (SD 1.7) for each assessment. Eighty-five percent of participants reported the intervention helped change behaviors. Intervention participants reduced their sedentary time by 4.37 (SD = 7.14) hours/day versus controls (p =.05), reduced fast food intake by 1.5 servings (p = 0.008), and increased vigorous activity by 0.56 (SD = 28.10) minutes, which was non-significant (p = 0.959). Findings show feasibility and acceptability and potential of the intervention to positively impact physical activity among AA BC survivors.