mHealth systems are promising tools for supporting asthma self-management and a user-centred design may improve compliance. We have determined the opinions of people with asthma and healthcare professionals (HCPs) on the use and functionality of mHealth self-management systems, initially by recruiting to focus groups. After framework analysis of the transcripts the resultant questionnaire was sent out to 186 people with asthma (91 uncontrolled) and 63 HCPs. Patients most frequently responded that they would like a mHealth system that allows them to monitor their asthma over time (72%) and that can collect data to present to their healthcare teams (70%). A system to alert patients to deteriorating asthma control (86%) and advising them when to seek medical attention (87%) were most frequently selected by HCPs. Patients were less likely than HCPs to believe that measuring medication adherence, inhaler technique and respiratory symptoms could help them achieve better asthma control. Furthermore, patients with uncontrolled asthma were more likely to believe that alerts to adverse environmental conditions, and low/high temperature and humidity, would be helpful in managing their asthma. In summary, this study provides insights from the perspective of patients and HCPs with regards to the use of mHealth systems for asthma self-management, which should be considered during the development of new mHealth systems