Despite major improvements over the past several decades, many patients undergoing hematopoietic stem cell transplantations (HSCT) continue to suffer from significant treatment-related morbidity and mortality. Clinical research studies (trials) have been integral to advancing the standard of care in HSCT. However, 1 of the biggest challenges with clinical trials is the low participation rate. Although barriers to participation in cancer clinical trials have been previously explored, studies specific to HSCT are lacking. The current study was undertaken to examine the knowledge, attitudes, and perceptions of HSCT patients regarding clinical trials. As members of focus groups, participants responded to open-ended questions that assessed factors influencing decision-making about HSCT clinical trials. Suggestions for improvements in the recruitment process were also solicited among participants. Seventeen adult HSCT patients and 6 parents of pediatric HSCT patients participated in the study. The median age was 56 years (range, 18 to 70) and 44 years (range, 28 to 54) for adult patients and parents, respectively. Participants universally indicated that too much information was provided within the informed consents and they were intimidated by the medical and legal language. Despite the large amount of information provided to them at the time of study enrollment, the participants had limited knowledge retention and recall of study details. Nevertheless, participants reported overall positive experiences with clinical trial participation and many would readily choose to participate again. A common concern among participants was the uncertainty of study outcome and general lack of feedback about results at the end of the study. Participants suggested that investigators provide more condensed and easier to understand informed consents and follow-up of study findings. These findings could be used to help guide the development of improved consent documents and enhanced participation in research studies, thereby affecting the future design of HSCT research protocols. (C) 2014 American Society for Blood and Marrow Transplantation.