Adolescent and young adult (AYA) cancer patients enroll in therapeutic clinical trials at low rates. Prior study has focused on trial availability; this research attempts to elucidate the role of communication in individual decision-making. We surveyed 193 AYA patients and reviewed medical records of informed consent discussions. Twenty percent (38/193) of patients were offered trials, 58% (22/38) enrolled. Many were unable to correctly identify whether they were offered trials or enrolled, including 27% (6/22) of patients on clinical trials who believed that they were not. Efforts to improve communication have potential to enhance informed decision-making in this vulnerable population.