Qualitative methodologies have multiple contributions to health research, including improving baseline understanding in new areas of enquiry; questioning existing assumptions; understanding viewpoints of specific subgroups; and offering complex, contextual information. While the role of qualitative research within mixed methods approaches is well documented, the contribution to clinical trial design and conduct is less well recognized. The Australian Palliative Care Clinical Studies Collaborative and Cancer Symptom Trials have developed a framework to detail how qualitative research might contribute to each key aspect of clinical trials. This practical framework provides real-world examples, including sample qualitative questions, to consider at each phase of controlled clinical trial development. As the number of randomized clinical trials in palliative care increases, a readily accessible approach to integrating qualitative research into clinical trial design and conduct is needed so that its full potential for improving study recruitment, conduct, outcomes, interpretation, and implementation may be realized.