The cross-sectional study enrolled 231 patients with heart failure (n = 115; 60.87% were men; mean age, 74.34 +/- 12.70 years) and heart transplantation (n = 116; 72.41% were men; mean age, 56.85 +/- 11.87 years) who self-reported their technology usage, physical activity, and source of motivation for exercise. Patients with heart failure were significantly older (P = .0001) than patients with heart transplantation. Physical activity levels in patients with heart failure decreased as the New York Heart Association classification increased. Patients with heart failure reported significantly lower physical activity than patients with heart transplantation (P = .0008). Smartphones were the most widely used electronic device to access the Internet in both groups. Patients with heart transplantation seemed to use more than one device to access the Internet. In both groups, patients reporting more technology usage also reported higher levels of physical activity. Patients who accessed the Internet daily reported lower levels of physical activity. Whereas patients with heart failure identified encouragement by family members as a source of motivation for exercise, patients with heart transplantation reported that they were likely to exercise if motivated by their healthcare provider. Patients with heart failure and heart transplantation have unique technological and motivational needs that need consideration for mobile health-driven interventions.