Use of digital health technologies (DHT) in chronic disease management is rising. We aim to evaluate the impact of DHT on clinical outcomes from randomized controlled trials (RCTs) of patients with heart failure (HF) and diabetes mellitus (DM). Electronic databases were searched for DHT RCTs in patients with HF and DM until February 2021. Patient characteristics and outcomes were analyzed. One published ( N = 519) and 6 registered ( N = 3423) eligible studies were identified, with one study exclusively including HF and DM patients. Median DHT monitoring was 12 months, with six studies using mobile platforms as their key exposure. Clinical outcomes included quality-of-life or self-care surveys ( n = 1 each), physical activity metrics, changes in biomarkers, and other clinical endpoints ( n = 3). Limited data exist on RCTs evaluating DHT in patients with concomitant HF and DM. Further work should define standardized clinical endpoints and platforms that can manage patients with multiple comorbidities. Graphical abstract