Providing patients with adequate information produces better medical outcomes, less distress, higher quality of life, and better preparation for active involvement in treatment—benefits that have energized research on the effective delivery of information to patients. For the most part, this research has focused on information and statistics relevant to treatment and prognosis. However, patients are increasingly coming into contact with another form of information about which little is known —namely, information describing the experiences of fellow cancer patients, or experiential information. For instance, the Internet makes this information available through patient-oriented chat rooms, bulletin boards, and a growing number of popular Web sites featuring survivors’ stories, case studies, and testimonials. Apart from the Internet, patients learn about other patients’ experiences in the popular media and through peer mentoring or buddy programs made available by treatment centers or cancer organizations. These programs enable patients to receive encouragement, support, and guidance from people with first-hand knowledge of the difficulties and fears they may be experiencing. Peer mentors may, or may not, be formally trained and are free to share any aspect of their experience they deem helpful, including information about their treatment decisions, effects of treatment, coping strategies, and recovery obstacles. In so doing, they attempt to communicate both factual information and information about normal or desirable ways to respond to cancer. Generally speaking, patients like getting experiential information, and many former patients enjoy providing it. At the same time, the informational content of peer mentoring and survivors’ stories has the potential to influence patients in significant ways. Yet little is known about how patients use this information or how it affects them. When does it give them hope, and when does it frighten them? Does it facilitate, or complicate, decision making? Under what circumstances is it helpful versus harmful? To begin investigating the answers to such questions, cancer patients’ responses to interview questions assessing how they communicated their thoughts and emotions during treatment were analyzed. Participants consisted of 20 men and 10 women completing a screening protocol for a multisite trial testing a psychological intervention for hematopoietic stem-cell transplant (HSCT) survivors. All study procedures were approved by the institutional review boards at the study sites, and patients provided signed informed consent. All patients had undergone HSCT 1 to 3 years earlier to treat hematologic malignancies such as multiple myeloma, lymphoma, and leukemia, and all were English speakers who were at least 18 years old at recruitment and at least 16 years old at transplantation. They were, on average, 54 years old, married (n 25), white (n 25), and well-educated (22 had college or graduate degrees). Most (n 25) reported an annual household income of more than $80,000. Content analysis of their responses to interview questions identified 10 functions of communication. Of the four most commonly mentioned functions, three prominently featured contact with other patients and/or exposure to information about their experiences: preparatory coping, social comparison, and negative effects. This article focuses on results involving these three functions of communication because of their relevance for understanding the effects of experiential information on cancer patients.