BACKGROUND: Physicians worry that disclosure of prognostic information can be distressing and deprive families of hope. Retrospective studies have shown that prognostic disclosure does not abrogate hope, but prospective data are lacking. OBJECTIVE: The study objective was to prospectively evaluate responses to prognosis communication among parents of children with advanced cancer. DESIGN: For this qualitative study we audiotaped conversations between clinicians and parents of children with newly relapsed or refractory cancer, and then interviewed parents about experiences with prognosis communication. Parents were asked to reflect on physician statements about prognosis. SETTING/SUBJECTS: Subjects were 32 pairs of parents and clinicians of children with relapsed or refractory cancer treated at Dana-Farber/Boston Children’s Center for Cancer and Blood Disorders, Boston, Massachusetts. RESULTS: Prognosis was discussed in 28/32 conversations (88%). Although most parents (N = 22, 69%) found prognostic information upsetting, most also valued honest communication about prognosis (N = 22, 69%.) Parents noted that frank disclosure fostered hope by relieving uncertainty and allowing them to make the best possible decisions for their children. Excessive optimism or a lack of information, in contrast, was sometimes experienced as a threat to hope and the parent-clinician relationship. A minority of parents were upset by clinician communication about prognosis (N = 4, 12%), but most did not consider the clinician responsible for their distress. Rather, parents attributed distress to the difficult situation. CONCLUSIONS: Many parents consider prognosis communication to be both difficult and necessary. While upsetting, prognostic information engenders hope by helping parents feel prepared to do their best for their children in the difficult days to come.