Background: ENABLE (Educate, Nurture, Advise Before Life Ends) II was one of the first randomized controlled trials (RCTs) examining the effects of a concurrent oncology palliative care intervention on quality of life, mood, and symptom control for advanced cancer patients and their caregivers. However, little is known about how participants experience early palliative care and the benefits and burdens of participating in a palliative care clinical trial. Aim: To gain a deeper understanding of participants' perspectives of the intervention and palliative care trial participation. Design: A qualitative descriptive study using thematic analysis to determine benefits and burdens of a new palliative care intervention and trial participation. Setting/participants: Of the 72 participants who were alive when the study commenced, 53 agreed to complete an in-depth, semistructured interview regarding the ENABLE II intervention and clinical trial participation. Results: Participants' perceptions of intervention benefits were represented by four themes: enhanced problem-solving skills, better coping, feeling empowered, and feeling supported or reassured. Three themes related to trial participation: helping future patients and contributing to science, gaining insight through completion of questionnaires, and trial/intervention aspects to improve. Conclusions: The benefits of the intervention and the positive aspects of trial participation outweighed trial "burdens". This study raises additional important questions relevant to future trial design and intervention development: when should a palliative care intervention be initiated and what aspects of self-care and healthy living should be offered in addition to palliative content for advanced cancer patients when they are feeling well? © The Author(s) 2012.