PURPOSE OF THE STUDY: ASyMS((c)) is an advanced symptom management system utilising mobile phone technology for patients to report cancer chemotherapy-related symptoms. The aim of this paper is to present health professionals involvement in the development of ASyMS((c)) for use with young people (YG) and evaluate their perceptions of the system. STAGE 1: Health professionals reviewed the symptoms chosen by young people to be included on the personal digital assistant questionnaire to confirm they would have universal relevance. These included: mouth sores, nausea, diarrhoea, vomiting and weight loss. STAGE 2: Health professionals completed a questionnaire prior to the study commencing, which suggested they felt ASyMS((c))-YG would give young people control and facilitate timely interventions when symptoms occur. Post-study perceptions were sought through semi-structured interviews and consultation sessions with 23 health professionals. These showed two over-arching themes: young people's symptoms and perceptions of ASyMS((c))-YG; and six sub-themes: increased control for young people; enhances communication between young people and health professionals; and helps with professional early intervention; increased support for young people; improve knowledge and understanding; technology appealing to young people. CONCLUSIONS: This early development work indicates that ASyMS((c))-YG is acceptable to health professionals and their perceptions of the system were overall very positive. Health professionals will continue to be involved in the study through developing self-care guidelines and alert system, which will be tested in an exploratory trial (stage 3) and randomised controlled trial (stage 4) in the future