The Whole System Demonstrator programme evaluated the use of telehealth and telecare to improve care for people with long-term conditions. It was the largest randomized controlled trial of telehealth/telecare in the world, involving over 6,000 people across several sites in the UK. The results showed that technology can help manage long-term conditions when integrated into redesigned care systems and combined with clinical engagement. However, successful implementation requires addressing organizational challenges, building trust with patients, and focusing on more than just introducing new devices. The findings support telehealth/telecare as part of improving care for the growing number of people with long-term conditions.