Recent co-design initiatives demonstrate successful healthcare innovation and improvement without the need for designers, potentially problematising design’s legitimacy in and contribution to this sector. In arguing the case for design, the author explores design’s value in the healthcare research domain, where the randomised controlled trial is regarded as the gold standard for scientific evidence. Two case studies are presented, one of the development of a visual tool for stroke rehabilitation, the other of a food- management and nutrition- monitoring system, describing design’s contributions within larger multidisciplinary healthcare research teams. These illustrate the value of designers’ methods in generating visual narratives and physical prototypes and their role in simultaneously eliciting and embodying particular forms of evidence while making progress in providing a tangible and interactive glimpse of the future.