Cardiovascular disease (CVD) is the most common cause of mortality in Ireland, accounting for one third of all deaths and one in five premature deaths [1]. With the prevalence of CVD so high, not only in Ireland but across the world, cardiac rehabilitation has never been so important as a continuous process of care. The main purpose of cardiac rehabilitation is to prevent a further cardiac event and improve the person’s quality of life. However, uptake of such programmes remains low. mHealth technologies may tackle some of the issues relating to poor uptake and low adherence, such as accessibility and affordability. This paper outlines the formative research process to develop a mobile-application for cardiovascular rehabilitation. [1] Department of Health and Children. (2010). Changing Cardiovascular Health. National Cardiovascular Health Policy 2010-2019. Dublin: Government Publications.