This paper describes a qualitative study conducted in the context of developing a novel ePRO (electronic Patient Reported Outcome) based palliative care intervention for cancer patients. The aim of the study was to elicit end-users’ needs, judgements of the MyPal system and recommendations for improvement. A participatory design was chosen as the value of this approach has been well established in eHealth systems’ design as well as the development of novel healthcare services. Focus groups with Chronic Lymphocytic Leukemia (CLL) patients were conducted at the Centre for Research and Technology (CERTH) in Greece using specially designed vignettes and discussion guides. Findings revealed that patients saw MyPal offering increased, direct contact with the healthcare team, freedom of physical and psychological symptom reporting as well as valid and reliable information. However, they had concerns about the appropriate use of data collected by MyPal, the efficiency of data analysis and data security adopted for sensitive personal information. The participatory design approach used has been very useful in encouraging the genuine involvement of participants, a factor which over time can empower and promote participants’ long-term engagement.