Background: In questionnaire-based research, human subject protection committees must assess the emotional impact of the study on participants. Without clear data about the risks and benefits of participating in such studies, however, review board members must use personal judgment to assess emotional harm. Objective: To examine experiences of distress and value of participation in a study of prognosis communication among parents of children with cancer, and to identify factors associated with predominantly distressing research experiences. Methods: We surveyed 194 parents of children with cancer (overall response rate, 70%), treated at the DanaFarber Cancer Institute and Children's Hospital, Boston, Mass, in the first year after the child's cancer diagnosis. The survey focused on the child's prognosis and parent-physician communication; at the end, we asked parents how distressing and how useful completing the survey had been to them personally. Results: Only 1% of parents found research participation to be ''very'' distressing. The majority of parents were ''not at all'' distressed by participating (62%), and most reported that the questionnaire was at least ''a little'' useful to them personally (69%). Overall, 18% of parents gave higher ratings for distress than for utility. Parents were more likely to experience research participation as predominantly distressing when they found prognostic information to be upsetting (odds ratio [OR] 5.38, p = 0.005).