BACKGROUND: Although the majority of parents of children with cancer say they want prognostic information, to the authors’ knowledge little is known regarding how their desire for and experiences with prognosis communication change over time. METHODS: A longitudinal, prospective questionnaire-based cohort study of 156 parents of children with cancer treated at 2 academic pediatric hospitals was performed. Previously published scales were administered at the time of diagnosis and at 4 months and 12 months later. RESULTS: The majority of parents preferred to hear about prognosis in as much detail as possible throughout the first year after a diagnosis of cancer (87%, 85%, and 84%, respectively, at the time of diagnosis, 4 months, and 12 months). Although nearly no parents reported wanting less information (<5% at any time point), a significant percentage reported wanting more information at each time point (25%, 28%, and 24%, respectively, at the time of diagnosis, 4 months, and 12 months). The majority of parents reported having had new prognostic discussions with the physician at each time point (93%, 74%, and 81%, respectively, at the time of diagnosis, 4 months, and 12 months). Irrespective of prognosis, parents were more likely to be satisfied with prognostic communication when physicians provided more extensive disclosure at the time of diagnosis (odds ratio, 1.85 per element of disclosure; 95% confidence interval, 1.25-2.74 [P =.002]) and when physicians discussed prognosis again before 4 months (odds ratio, 8.71; 95% confidence interval, 2.64-28.72 [P =.0004]). CONCLUSIONS: The majority of parents wanted detailed, longitudinal prognostic conversations; nearly none of the parents preferred less prognostic information. A return to these conversations over time can help rather than hurt parents. Future studies should assess the ideal contents of these longitudinal discussions, and the communication preferences of pediatric patients. Cancer 2017;123:4031-8.